[v3,RISC-V] Generate Zicond instruction for select pattern with condition eq or neq to 0

Message ID 20230802013813.14284-1-zengxiao@eswincomputing.com
State Accepted
Headers
Series [v3,RISC-V] Generate Zicond instruction for select pattern with condition eq or neq to 0 |

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Context Check Description
snail/gcc-patch-check success Github commit url

Commit Message

Xiao Zeng Aug. 2, 2023, 1:38 a.m. UTC
  This patch recognizes Zicond patterns when the select pattern
with condition eq or neq to 0 (using eq as an example), namely:

1 rd = (rs2 == 0) ? non-imm : 0
2 rd = (rs2 == 0) ? non-imm : non-imm
3 rd = (rs2 == 0) ? reg : non-imm
4 rd = (rs2 == 0) ? reg : reg

gcc/ChangeLog:

        * config/riscv/riscv.cc (riscv_expand_conditional_move): Recognize
        Zicond patterns
        * config/riscv/riscv.md: Recognize Zicond patterns through mov<mode>cc

gcc/testsuite/ChangeLog:

        * gcc.target/riscv/zicond-primitiveSemantics_return_0_imm.c: New test.
        * gcc.target/riscv/zicond-primitiveSemantics_return_imm_imm.c: New test.
        * gcc.target/riscv/zicond-primitiveSemantics_return_imm_reg.c: New test.
        * gcc.target/riscv/zicond-primitiveSemantics_return_reg_reg.c: New test.
---
 gcc/config/riscv/riscv.cc                     | 137 ++++++++++++++++++
 gcc/config/riscv/riscv.md                     |   4 +-
 .../zicond-primitiveSemantics_return_0_imm.c  |  65 +++++++++
 ...zicond-primitiveSemantics_return_imm_imm.c |  73 ++++++++++
 ...zicond-primitiveSemantics_return_imm_reg.c |  65 +++++++++
 ...zicond-primitiveSemantics_return_reg_reg.c |  65 +++++++++
 6 files changed, 407 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_0_imm.c
 create mode 100644 gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_imm_imm.c
 create mode 100644 gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_imm_reg.c
 create mode 100644 gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_reg_reg.c
  

Comments

Jeff Law Aug. 3, 2023, 8:19 p.m. UTC | #1
On 8/1/23 19:38, Xiao Zeng wrote:
> This patch recognizes Zicond patterns when the select pattern
> with condition eq or neq to 0 (using eq as an example), namely:
> 
> 1 rd = (rs2 == 0) ? non-imm : 0
> 2 rd = (rs2 == 0) ? non-imm : non-imm
> 3 rd = (rs2 == 0) ? reg : non-imm
> 4 rd = (rs2 == 0) ? reg : reg
> 
> gcc/ChangeLog:
> 
>          * config/riscv/riscv.cc (riscv_expand_conditional_move): Recognize
>          Zicond patterns
>          * config/riscv/riscv.md: Recognize Zicond patterns through mov<mode>cc
> 
> gcc/testsuite/ChangeLog:
> 
>          * gcc.target/riscv/zicond-primitiveSemantics_return_0_imm.c: New test.
>          * gcc.target/riscv/zicond-primitiveSemantics_return_imm_imm.c: New test.
>          * gcc.target/riscv/zicond-primitiveSemantics_return_imm_reg.c: New test.
>          * gcc.target/riscv/zicond-primitiveSemantics_return_reg_reg.c: New test.
So I've done a partial commit of this patch.  I'm still evaluating a few 
of the cases and haven't included them yet.

The most notable change I've made is the 0, imm case and imm, 0 case can 
trivially handle 0, reg and reg, 0 as well.  I also changed the imm, imm 
case to use gen_int_mode rather than GEN_INT.  It may not be strictly 
necessary here, but it does future proof the code a bit if we were to 
support additional mode (and we may well want to do that).

I'm hoping to get the rest of patch #3 in today, though I suspect the 
testing will push it into tomorrow.  Then I want to layer on Raphael's 
code to handle missed cases using scc insns.

Jeff
commit 9e3fd332959930efd3cabf222afbac910507d2f3
Author: Xiao Zeng <zengxiao@eswincomputing.com>
Date:   Thu Aug 3 16:09:46 2023 -0400

    [PATCH 3/5] [RISC-V] Generate Zicond instruction for select pattern with condition eq or neq to 0
    
    [ This is a partial commit.  So not all the cases mentioned by
      Xiao are currently handled. ]
    
    This patch recognizes Zicond patterns when the select pattern
    with condition eq or neq to 0 (using eq as an example), namely:
    
    1 rd = (rs2 == 0) ? non-imm : 0
    2 rd = (rs2 == 0) ? non-imm : non-imm
    3 rd = (rs2 == 0) ? reg : non-imm
    4 rd = (rs2 == 0) ? reg : reg
    
    gcc/ChangeLog:
    
            * config/riscv/riscv.cc (riscv_expand_conditional_move): Recognize
            various Zicond patterns.
            * config/riscv/riscv.md (mov<mode>cc): Allow TARGET_ZICOND.  Use
            sfb_alu_operand for both arms of the conditional move.
    
            Co-authored-by: Jeff Law <jlaw@ventanamicro.com>

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index d8fab68dbb4..8b725610815 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -3580,15 +3580,67 @@ riscv_expand_conditional_move (rtx dest, rtx op, rtx cons, rtx alt)
       riscv_emit_int_compare (&code, &op0, &op1, need_eq_ne_p);
       rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
 
-      /* The expander allows (const_int 0) for CONS for the benefit of
-	 TARGET_XTHEADCONDMOV, but that case isn't supported for
-	 TARGET_SFB_ALU.  So force that operand into a register if
-	 necessary.  */
+      /* The expander is a bit loose in its specification of the true
+	 arm of the conditional move.  That allows us to support more
+	 cases for extensions which are more general than SFB.  But
+	does mean we need to force CONS into a register at this point.  */
       cons = force_reg (GET_MODE (dest), cons);
       emit_insn (gen_rtx_SET (dest, gen_rtx_IF_THEN_ELSE (GET_MODE (dest),
 							  cond, cons, alt)));
       return true;
     }
+  else if (TARGET_ZICOND
+	   && (code == EQ || code == NE)
+	   && GET_MODE_CLASS (mode) == MODE_INT)
+    {
+      /* The comparison must be comparing WORD_MODE objects.   We must
+	 enforce that so that we don't strip away a sign_extension
+	 thinking it is unnecessary.  We might consider using
+	 riscv_extend_operands if they are not already properly extended.  */
+      if (GET_MODE (op0) != word_mode || GET_MODE (op1) != word_mode)
+	return false;
+
+      /* 0, reg or 0, imm */
+      if (cons == CONST0_RTX (mode)
+	  && (REG_P (alt)
+	      || (CONST_INT_P (alt) && alt != CONST0_RTX (mode))))
+	{
+	  riscv_emit_int_compare (&code, &op0, &op1, true);
+	  rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+	  alt = force_reg (mode, alt);
+	  emit_insn (gen_rtx_SET (dest,
+				  gen_rtx_IF_THEN_ELSE (mode, cond,
+							cons, alt)));
+	  return true;
+	}
+      /* imm, imm */
+      else if (CONST_INT_P (cons) && cons != CONST0_RTX (mode)
+	       && CONST_INT_P (alt) && alt != CONST0_RTX (mode))
+	{
+	  riscv_emit_int_compare (&code, &op0, &op1, true);
+	  rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+	  HOST_WIDE_INT t = INTVAL (alt) - INTVAL (cons);
+	  alt = force_reg (mode, gen_int_mode (t, mode));
+	  emit_insn (gen_rtx_SET (dest,
+				  gen_rtx_IF_THEN_ELSE (mode, cond,
+							CONST0_RTX (mode),
+							alt)));
+	  riscv_emit_binary (PLUS, dest, dest, cons);
+	  return true;
+	}
+      /* reg, 0 or imm, 0  */
+      else if ((REG_P (cons)
+		|| (CONST_INT_P (cons) && cons != CONST0_RTX (mode)))
+	       && alt == CONST0_RTX (mode))
+	{
+	  riscv_emit_int_compare (&code, &op0, &op1, true);
+	  rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+	  cons = force_reg (mode, cons);
+	  emit_insn (gen_rtx_SET (dest, gen_rtx_IF_THEN_ELSE (mode, cond,
+							      cons, alt)));
+	  return true;
+	}
+    }
 
   return false;
 }
diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index 24819cc737c..688fd697255 100644
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -2492,9 +2492,9 @@ (define_insn "*branch<mode>"
 (define_expand "mov<mode>cc"
   [(set (match_operand:GPR 0 "register_operand")
 	(if_then_else:GPR (match_operand 1 "comparison_operator")
-			  (match_operand:GPR 2 "reg_or_0_operand")
+			  (match_operand:GPR 2 "sfb_alu_operand")
 			  (match_operand:GPR 3 "sfb_alu_operand")))]
-  "TARGET_SFB_ALU || TARGET_XTHEADCONDMOV"
+  "TARGET_SFB_ALU || TARGET_XTHEADCONDMOV || TARGET_ZICOND"
 {
   if (riscv_expand_conditional_move (operands[0], operands[1],
 				     operands[2], operands[3]))
  
Jeff Law Aug. 4, 2023, 9:31 p.m. UTC | #2
On 8/1/23 19:38, Xiao Zeng wrote:
> This patch recognizes Zicond patterns when the select pattern
> with condition eq or neq to 0 (using eq as an example), namely:
> 
> 1 rd = (rs2 == 0) ? non-imm : 0
> 2 rd = (rs2 == 0) ? non-imm : non-imm
> 3 rd = (rs2 == 0) ? reg : non-imm
> 4 rd = (rs2 == 0) ? reg : reg
> 
> gcc/ChangeLog:
> 
>          * config/riscv/riscv.cc (riscv_expand_conditional_move): Recognize
>          Zicond patterns
>          * config/riscv/riscv.md: Recognize Zicond patterns through mov<mode>cc
So I've made minor adjustments to the remaining three cases.  First we 
need to check the code before optimizing the cases were one of the arms 
of the conditional move matches op0.

I slightly adjusted the case for out of range constants.  Its better to 
check SMALL_OPERAND rather than testing for specific constants.  And 
when that triggers, we can just force the value into a register and 
continue as-is rather than recursing.

The patch I'm committing fixes one comment typo (whitespace) and a bit 
of accidentally duplicated code I added in a prior commit.

Next up Raphael's patches to handle nontrival conditionals by emiting an 
scc insn :-)

Jeff

ps.  I'm deferrring the testsuite bits until we sort out the costing 
problems.  THey're definitely not forgotten and I still use them in my 
local tree.
commit 4e87c953d16377457b31b65b6c3268d932e462ab
Author: Xiao Zeng <zengxiao@eswincomputing.com>
Date:   Fri Aug 4 17:23:56 2023 -0400

    [PATCH v3] [RISC-V] Generate Zicond instruction for select pattern with condition eq or neq to 0
    
    This patch recognizes Zicond patterns when the select pattern
    with condition eq or neq to 0 (using eq as an example), namely:
    
    1 rd = (rs2 == 0) ? non-imm : 0
    2 rd = (rs2 == 0) ? non-imm : non-imm
    3 rd = (rs2 == 0) ? reg : non-imm
    4 rd = (rs2 == 0) ? reg : reg
    
    gcc/ChangeLog:
    
            * config/riscv/riscv.cc (riscv_expand_conditional_move): Recognize
            more Zicond patterns.  Fix whitespace typo.
            (riscv_rtx_costs): Remove accidental code duplication.
    
            Co-authored-by: Jeff Law <jlaw@ventanamicro.com>

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index 8b725610815..7728cd34569 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -2522,20 +2522,6 @@ riscv_rtx_costs (rtx x, machine_mode mode, int outer_code, int opno ATTRIBUTE_UN
 	  *total = COSTS_N_INSNS (1);
 	  return true;
 	}
-      else if (TARGET_ZICOND
-	       && outer_code == SET
-	       && ((GET_CODE (XEXP (x, 1)) == REG
-		    && XEXP (x, 2) == CONST0_RTX (GET_MODE (XEXP (x, 1))))
-		   || (GET_CODE (XEXP (x, 2)) == REG
-		       && XEXP (x, 1) == CONST0_RTX (GET_MODE (XEXP (x, 2))))
-		   || (GET_CODE (XEXP (x, 1)) == REG
-		       && rtx_equal_p (XEXP (x, 1), XEXP (XEXP (x, 0), 0)))
-		   || (GET_CODE (XEXP (x, 1)) == REG
-		       && rtx_equal_p (XEXP (x, 2), XEXP (XEXP (x, 0), 0)))))
-	{
-	  *total = COSTS_N_INSNS (1);
-	  return true;
-	}
       else if (LABEL_REF_P (XEXP (x, 1)) && XEXP (x, 2) == pc_rtx)
 	{
 	  if (equality_operator (XEXP (x, 0), mode)
@@ -3583,7 +3569,7 @@ riscv_expand_conditional_move (rtx dest, rtx op, rtx cons, rtx alt)
       /* The expander is a bit loose in its specification of the true
 	 arm of the conditional move.  That allows us to support more
 	 cases for extensions which are more general than SFB.  But
-	does mean we need to force CONS into a register at this point.  */
+	 does mean we need to force CONS into a register at this point.  */
       cons = force_reg (GET_MODE (dest), cons);
       emit_insn (gen_rtx_SET (dest, gen_rtx_IF_THEN_ELSE (GET_MODE (dest),
 							  cond, cons, alt)));
@@ -3628,6 +3614,40 @@ riscv_expand_conditional_move (rtx dest, rtx op, rtx cons, rtx alt)
 	  riscv_emit_binary (PLUS, dest, dest, cons);
 	  return true;
 	}
+      /* imm, reg  */
+      else if (CONST_INT_P (cons) && cons != CONST0_RTX (mode) && REG_P (alt))
+	{
+	  /* Optimize for register value of 0.  */
+	  if (code == NE && rtx_equal_p (op0, alt) && op1 == CONST0_RTX (mode))
+	    {
+	      rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+	      cons = force_reg (mode, cons);
+	      emit_insn (gen_rtx_SET (dest,
+				      gen_rtx_IF_THEN_ELSE (mode, cond,
+							    cons, alt)));
+	      return true;
+	    }
+
+	  riscv_emit_int_compare (&code, &op0, &op1, true);
+	  rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+
+	  rtx temp1 = gen_reg_rtx (mode);
+	  rtx temp2 = gen_int_mode (-1 * INTVAL (cons), mode);
+
+	  /* TEMP2 might not fit into a signed 12 bit immediate suitable
+	     for an addi instruction.  If that's the case, force it into
+	     a register.  */
+	  if (!SMALL_OPERAND (INTVAL (temp2)))
+	    temp2 = force_reg (mode, temp2);
+
+	  riscv_emit_binary (PLUS, temp1, alt, temp2);
+	  emit_insn (gen_rtx_SET (dest,
+				  gen_rtx_IF_THEN_ELSE (mode, cond,
+							CONST0_RTX (mode),
+							temp1)));
+	  riscv_emit_binary (PLUS, dest, dest, cons);
+	  return true;
+	}
       /* reg, 0 or imm, 0  */
       else if ((REG_P (cons)
 		|| (CONST_INT_P (cons) && cons != CONST0_RTX (mode)))
@@ -3640,6 +3660,73 @@ riscv_expand_conditional_move (rtx dest, rtx op, rtx cons, rtx alt)
 							      cons, alt)));
 	  return true;
 	}
+      /* reg, imm  */
+      else if (REG_P (cons) && CONST_INT_P (alt) && alt != CONST0_RTX (mode))
+	{
+	  /* Optimize for register value of 0.  */
+	  if (code == EQ && rtx_equal_p (op0, cons) && op1 == CONST0_RTX (mode))
+	    {
+	      rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+	      alt = force_reg (mode, alt);
+	      emit_insn (gen_rtx_SET (dest,
+				      gen_rtx_IF_THEN_ELSE (mode, cond,
+							    cons, alt)));
+	      return true;
+	    }
+
+	  riscv_emit_int_compare (&code, &op0, &op1, true);
+	  rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+
+	  rtx temp1 = gen_reg_rtx (mode);
+	  rtx temp2 = gen_int_mode (-1 * INTVAL (alt), mode);
+
+	  /* TEMP2 might not fit into a signed 12 bit immediate suitable
+	     for an addi instruction.  If that's the case, force it into
+	     a register.  */
+	  if (!SMALL_OPERAND (INTVAL (temp2)))
+	    temp2 = force_reg (mode, temp2);
+
+	  riscv_emit_binary (PLUS, temp1, cons, temp2);
+	  emit_insn (gen_rtx_SET (dest,
+				  gen_rtx_IF_THEN_ELSE (mode, cond,
+							temp1,
+							CONST0_RTX (mode))));
+	  riscv_emit_binary (PLUS, dest, dest, alt);
+	  return true;
+	}
+      /* reg, reg  */
+      else if (REG_P (cons) && REG_P (alt))
+	{
+	  if ((code == EQ && rtx_equal_p (cons, op0))
+	       || (code == NE && rtx_equal_p (alt, op0)))
+	    {
+	      rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+	      if (!rtx_equal_p (cons, op0))
+		std::swap (alt, cons);
+	      alt = force_reg (mode, alt);
+	      emit_insn (gen_rtx_SET (dest,
+				      gen_rtx_IF_THEN_ELSE (mode, cond,
+							    cons, alt)));
+	      return true;
+	    }
+
+	  rtx reg1 = gen_reg_rtx (mode);
+	  rtx reg2 = gen_reg_rtx (mode);
+	  riscv_emit_int_compare (&code, &op0, &op1, true);
+	  rtx cond1 = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+	  rtx cond2 = gen_rtx_fmt_ee (code == NE ? EQ : NE,
+				      GET_MODE (op0), op0, op1);
+	  emit_insn (gen_rtx_SET (reg2,
+				  gen_rtx_IF_THEN_ELSE (mode, cond2,
+							CONST0_RTX (mode),
+							cons)));
+	  emit_insn (gen_rtx_SET (reg1,
+				  gen_rtx_IF_THEN_ELSE (mode, cond1,
+							CONST0_RTX (mode),
+							alt)));
+	  riscv_emit_binary (IOR, dest, reg1, reg2);
+	  return true;
+	}
     }
 
   return false;
  
Xiao Zeng Aug. 5, 2023, 9:37 a.m. UTC | #3
On Sat, Aug 05, 2023 at 05:31:00 AM  Jeff Law <jeffreyalaw@gmail.com> wrote:
>
>On 8/1/23 19:38, Xiao Zeng wrote:
>> This patch recognizes Zicond patterns when the select pattern
>> with condition eq or neq to 0 (using eq as an example), namely:
>>
>> 1 rd = (rs2 == 0) ? non-imm : 0
>> 2 rd = (rs2 == 0) ? non-imm : non-imm
>> 3 rd = (rs2 == 0) ? reg : non-imm
>> 4 rd = (rs2 == 0) ? reg : reg
>>
>> gcc/ChangeLog:
>>
>>          * config/riscv/riscv.cc (riscv_expand_conditional_move): Recognize
>>          Zicond patterns
>>          * config/riscv/riscv.md: Recognize Zicond patterns through mov<mode>cc
>So I've made minor adjustments to the remaining three cases.  First we
>need to check the code before optimizing the cases were one of the arms
>of the conditional move matches op0.
>
>I slightly adjusted the case for out of range constants.  Its better to
>check SMALL_OPERAND rather than testing for specific constants.  And
>when that triggers, we can just force the value into a register and
>continue as-is rather than recursing.
> 
These changes make the code more concise and readable. Thumbs up!

>The patch I'm committing fixes one comment typo (whitespace) and a bit
>of accidentally duplicated code I added in a prior commit.
>
>Next up Raphael's patches to handle nontrival conditionals by emiting an
>scc insn :-) 
It would be great to see other implementations for conditional execution. :-)

>
>Jeff
>
>ps.  I'm deferrring the testsuite bits until we sort out the costing
>problems.  THey're definitely not forgotten and I still use them in my
>local tree. 
Thank you Jeff, I look forward to a unified, complete and concise
implementation method for cost calculation as soon as possible.
 
Thanks
Xiao Zeng
  
Jeff Law Sept. 26, 2023, 6:43 p.m. UTC | #4
On 8/1/23 19:38, Xiao Zeng wrote:
> This patch recognizes Zicond patterns when the select pattern
> with condition eq or neq to 0 (using eq as an example), namely:
> 
> 1 rd = (rs2 == 0) ? non-imm : 0
> 2 rd = (rs2 == 0) ? non-imm : non-imm
> 3 rd = (rs2 == 0) ? reg : non-imm
> 4 rd = (rs2 == 0) ? reg : reg
> 
> gcc/ChangeLog:
> 
>          * config/riscv/riscv.cc (riscv_expand_conditional_move): Recognize
>          Zicond patterns
>          * config/riscv/riscv.md: Recognize Zicond patterns through mov<mode>cc
> 
> gcc/testsuite/ChangeLog:
> 
>          * gcc.target/riscv/zicond-primitiveSemantics_return_0_imm.c: New test.
>          * gcc.target/riscv/zicond-primitiveSemantics_return_imm_imm.c: New test.
>          * gcc.target/riscv/zicond-primitiveSemantics_return_imm_reg.c: New test.
>          * gcc.target/riscv/zicond-primitiveSemantics_return_reg_reg.c: New test.
I've added -Oz and -Og to the skip list and pushed the tests up to the 
trunk.

jeff
  

Patch

diff --git a/gcc/config/riscv/riscv.cc b/gcc/config/riscv/riscv.cc
index b6a57d0306d..6353d08ba9d 100644
--- a/gcc/config/riscv/riscv.cc
+++ b/gcc/config/riscv/riscv.cc
@@ -3557,6 +3557,143 @@  riscv_expand_conditional_move (rtx dest, rtx op, rtx cons, rtx alt)
 							  cond, cons, alt)));
       return true;
     }
+  else if (TARGET_ZICOND
+           && (code == EQ || code == NE)
+           && GET_MODE_CLASS (mode) == MODE_INT)
+    {
+      /* 0 + imm  */
+      if (CONST_INT_P (cons) && cons == CONST0_RTX (GET_MODE (cons))
+          && CONST_INT_P (alt) && alt != CONST0_RTX (GET_MODE (alt)))
+        {
+          riscv_emit_int_compare (&code, &op0, &op1, true);
+          rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+          alt = force_reg (mode, alt);
+          emit_insn (gen_rtx_SET (dest, gen_rtx_IF_THEN_ELSE (mode, cond,
+                                                              cons, alt)));
+          return true;
+        }
+      /* imm + imm  */
+      else if (CONST_INT_P (cons) && cons != CONST0_RTX (GET_MODE (cons))
+               && CONST_INT_P (alt) && alt != CONST0_RTX (GET_MODE (alt)))
+        {
+          riscv_emit_int_compare (&code, &op0, &op1, true);
+          rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+          alt = force_reg (mode, GEN_INT (INTVAL (alt) - INTVAL (cons)));
+          emit_insn (gen_rtx_SET (dest, gen_rtx_IF_THEN_ELSE (mode, cond,
+                                                              CONST0_RTX (mode),
+                                                              alt)));
+          riscv_emit_binary (PLUS, dest, dest, cons);
+          return true;
+        }
+      /* imm + reg  */
+      else if (CONST_INT_P (cons) && cons != CONST0_RTX (GET_MODE (cons))
+               && REG_P (alt))
+        {    
+          if (op0 == alt && op1 == CONST0_RTX (GET_MODE (op1)))
+            {    
+              rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+              cons = force_reg (mode, cons);
+              emit_insn (gen_rtx_SET (dest, gen_rtx_IF_THEN_ELSE (mode, cond,
+                                                                  cons, alt)));
+              return true;
+            }
+          /* Handle the special situation of: -2048 == INTVAL (alt)
+             to avoid failure due to an unrecognized insn. Let the costing
+             model determine if the conditional move sequence is better
+             than the branching sequence.  */
+          if (-2048 == INTVAL (cons))
+            {
+              rtx reg = gen_reg_rtx (mode);
+              emit_insn (gen_rtx_SET (reg, cons));
+              return riscv_expand_conditional_move (dest, op, reg, alt);
+            }
+          riscv_emit_int_compare (&code, &op0, &op1, true);
+          rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+          rtx temp = GEN_INT (-1 * INTVAL (cons));
+          riscv_emit_binary (PLUS, alt, alt, temp);
+          emit_insn (gen_rtx_SET (dest, gen_rtx_IF_THEN_ELSE (mode, cond,
+                                                              CONST0_RTX (mode),
+                                                              alt)));
+          riscv_emit_binary (PLUS, dest, dest, cons);
+          return true;
+        }
+      /* imm + 0  */
+      else if (CONST_INT_P (cons) && cons != CONST0_RTX (GET_MODE (cons))
+               && CONST_INT_P (alt) && alt == CONST0_RTX (GET_MODE (alt)))
+        {
+          riscv_emit_int_compare (&code, &op0, &op1, true);
+          rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+          cons = force_reg (mode, cons);
+          emit_insn (gen_rtx_SET (dest, gen_rtx_IF_THEN_ELSE (mode, cond,
+                                                              cons, alt)));
+          return true;
+        }
+      /* reg + imm  */
+      else if (REG_P (cons) && CONST_INT_P (alt)
+               && alt != CONST0_RTX (GET_MODE (alt)))
+        {
+          if (op0 == cons && op1 == CONST0_RTX (GET_MODE (op1)))
+            {
+              rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+              alt = force_reg (mode, alt);
+              emit_insn (gen_rtx_SET (dest, gen_rtx_IF_THEN_ELSE (mode, cond,
+                                                                  cons, alt)));
+              return true;
+            }
+          if (-2048 == INTVAL (alt))
+            {
+              rtx reg = gen_reg_rtx (mode);
+              emit_insn (gen_rtx_SET (reg, alt));
+              return riscv_expand_conditional_move (dest, op, cons, reg);
+            }
+          riscv_emit_int_compare (&code, &op0, &op1, true);
+          rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+          rtx temp = GEN_INT (-1 * INTVAL (alt));
+          riscv_emit_binary (PLUS, cons, cons, temp);
+          emit_insn (gen_rtx_SET (dest,
+                                  gen_rtx_IF_THEN_ELSE (mode, cond, cons,
+                                                        CONST0_RTX (mode))));
+          riscv_emit_binary (PLUS, dest, dest, alt);
+          return true;
+        }
+      /* reg + reg  */
+      else if (REG_P (cons) && REG_P (alt))
+        {
+          if (op0 == cons && op1 == CONST0_RTX (GET_MODE (op1)))
+            {
+              rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+              emit_insn (gen_rtx_SET (dest,
+                                      gen_rtx_IF_THEN_ELSE (mode, cond,
+                                                            CONST0_RTX (mode),
+                                                            alt)));
+              return true;
+            }
+          if (op0 == alt && op1 == CONST0_RTX (GET_MODE (op1)))
+            {
+              rtx cond = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+              emit_insn (gen_rtx_SET (dest,
+                                      gen_rtx_IF_THEN_ELSE (mode, cond, cons,
+                                                            CONST0_RTX (mode))));
+              return true;
+            }
+          rtx reg1 = gen_reg_rtx (mode);
+          rtx reg2 = gen_reg_rtx (mode);
+          riscv_emit_int_compare (&code, &op0, &op1, true);
+          rtx cond1 = gen_rtx_fmt_ee (code, GET_MODE (op0), op0, op1);
+          rtx cond2 = gen_rtx_fmt_ee (code == NE ? EQ : NE,
+                                      GET_MODE (op0), op0, op1);
+          emit_insn (gen_rtx_SET (reg2,
+                                  gen_rtx_IF_THEN_ELSE (mode, cond2,
+                                                        CONST0_RTX (mode),
+                                                        cons)));
+          emit_insn (gen_rtx_SET (reg1,
+                                  gen_rtx_IF_THEN_ELSE (mode, cond1,
+                                                        CONST0_RTX (mode),
+                                                        alt)));
+          riscv_emit_binary (IOR, dest, reg1, reg2);
+          return true;
+        }
+    }
 
   return false;
 }
diff --git a/gcc/config/riscv/riscv.md b/gcc/config/riscv/riscv.md
index 24819cc737c..688fd697255 100644
--- a/gcc/config/riscv/riscv.md
+++ b/gcc/config/riscv/riscv.md
@@ -2492,9 +2492,9 @@ 
 (define_expand "mov<mode>cc"
   [(set (match_operand:GPR 0 "register_operand")
 	(if_then_else:GPR (match_operand 1 "comparison_operator")
-			  (match_operand:GPR 2 "reg_or_0_operand")
+			  (match_operand:GPR 2 "sfb_alu_operand")
 			  (match_operand:GPR 3 "sfb_alu_operand")))]
-  "TARGET_SFB_ALU || TARGET_XTHEADCONDMOV"
+  "TARGET_SFB_ALU || TARGET_XTHEADCONDMOV || TARGET_ZICOND"
 {
   if (riscv_expand_conditional_move (operands[0], operands[1],
 				     operands[2], operands[3]))
diff --git a/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_0_imm.c b/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_0_imm.c
new file mode 100644
index 00000000000..6e45b3f8ae5
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_0_imm.c
@@ -0,0 +1,65 @@ 
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gc_zicond -mabi=lp64d" { target { rv64 } } } */
+/* { dg-options "-march=rv32gc_zicond -mabi=ilp32f" { target { rv32 } } } */
+/* { dg-skip-if "" { *-*-* } {"-O0" "-Os"} } */
+
+long primitiveSemantics_return_0_imm_00(long a, long b) {
+  return a == 0 ? 0 : 3;
+}
+
+long primitiveSemantics_return_0_imm_01(long a, long b) {
+  return a != 0 ? 0 : 3;
+}
+
+long primitiveSemantics_return_0_imm_02(long a, long b) {
+  return a == 0 ? 3 : 0;
+}
+
+long primitiveSemantics_return_0_imm_03(long a, long b) {
+  return a != 0 ? 3 : 0;
+}
+
+long primitiveSemantics_return_0_imm_04(long a, long b) {
+  if (a)
+    b = 0;
+  else
+    b = 3;
+  return b;
+}
+
+long primitiveSemantics_return_0_imm_05(long a, long b) {
+  if (!a)
+    b = 0;
+  else
+    b = 3;
+  return b;
+}
+
+int primitiveSemantics_return_0_imm_06(int a, int b) { return a == 0 ? 0 : 3; }
+
+int primitiveSemantics_return_0_imm_07(int a, int b) { return a != 0 ? 0 : 3; }
+
+int primitiveSemantics_return_0_imm_08(int a, int b) { return a == 0 ? 3 : 0; }
+
+int primitiveSemantics_return_0_imm_09(int a, int b) { return a != 0 ? 3 : 0; }
+
+int primitiveSemantics_return_0_imm_10(int a, int b) {
+  if (a)
+    b = 0;
+  else
+    b = 3;
+  return b;
+}
+
+int primitiveSemantics_return_0_imm_11(int a, int b) {
+  if (!a)
+    b = 0;
+  else
+    b = 3;
+  return b;
+}
+
+/* { dg-final { scan-assembler-times "czero.eqz" 6 } } */
+/* { dg-final { scan-assembler-times "czero.nez" 6 } } */
+/* { dg-final { scan-assembler-not "beq" } } */
+/* { dg-final { scan-assembler-not "bne" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_imm_imm.c b/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_imm_imm.c
new file mode 100644
index 00000000000..ebdca521373
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_imm_imm.c
@@ -0,0 +1,73 @@ 
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gc_zicond -mabi=lp64d" { target { rv64 } } } */
+/* { dg-options "-march=rv32gc_zicond -mabi=ilp32f" { target { rv32 } } } */
+/* { dg-skip-if "" { *-*-* } {"-O0" "-Os"} } */
+
+long primitiveSemantics_return_imm_imm_00(long a, long b) {
+  return a == 0 ? 4 : 6;
+}
+
+long primitiveSemantics_return_imm_imm_01(long a, long b) {
+  return a != 0 ? 4 : 6;
+}
+
+long primitiveSemantics_return_imm_imm_02(long a, long b) {
+  return a == 0 ? 6 : 4;
+}
+
+long primitiveSemantics_return_imm_imm_03(long a, long b) {
+  return a != 0 ? 6 : 4;
+}
+
+long primitiveSemantics_return_imm_imm_04(long a, long b) {
+  if (a)
+    b = 4;
+  else
+    b = 6;
+  return b;
+}
+
+long primitiveSemantics_return_imm_imm_05(long a, long b) {
+  if (!a)
+    b = 4;
+  else
+    b = 6;
+  return b;
+}
+
+int primitiveSemantics_return_imm_imm_06(int a, int b) {
+  return a == 0 ? 4 : 6;
+}
+
+int primitiveSemantics_return_imm_imm_07(int a, int b) {
+  return a != 0 ? 4 : 6;
+}
+
+int primitiveSemantics_return_imm_imm_08(int a, int b) {
+  return a == 0 ? 6 : 4;
+}
+
+int primitiveSemantics_return_imm_imm_09(int a, int b) {
+  return a != 0 ? 6 : 4;
+}
+
+int primitiveSemantics_return_imm_imm_10(int a, int b) {
+  if (a)
+    b = 4;
+  else
+    b = 6;
+  return b;
+}
+
+int primitiveSemantics_return_imm_imm_11(int a, int b) {
+  if (!a)
+    b = 4;
+  else
+    b = 6;
+  return b;
+}
+
+/* { dg-final { scan-assembler-times "czero.eqz" 6 } } */
+/* { dg-final { scan-assembler-times "czero.nez" 6 } } */
+/* { dg-final { scan-assembler-not "beq" } } */
+/* { dg-final { scan-assembler-not "bne" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_imm_reg.c b/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_imm_reg.c
new file mode 100644
index 00000000000..12c351dbc16
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_imm_reg.c
@@ -0,0 +1,65 @@ 
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gc_zicond -mabi=lp64d" { target { rv64 } } } */
+/* { dg-options "-march=rv32gc_zicond -mabi=ilp32f" { target { rv32 } } } */
+/* { dg-skip-if "" { *-*-* } {"-O0" "-Os"} } */
+
+long primitiveSemantics_return_imm_reg_00(long a, long b) {
+  return a == 0 ? 1 : b;
+}
+
+long primitiveSemantics_return_imm_reg_01(long a, long b) {
+  return a != 0 ? 1 : b;
+}
+
+long primitiveSemantics_return_imm_reg_02(long a, long b) {
+  return a == 0 ? b : 1;
+}
+
+long primitiveSemantics_return_imm_reg_03(long a, long b) {
+  return a != 0 ? b : 1;
+}
+
+long primitiveSemantics_return_imm_reg_04(long a, long b) {
+  if (a)
+    b = 1;
+  return b;
+}
+
+long primitiveSemantics_return_imm_reg_05(long a, long b) {
+  if (!a)
+    b = 1;
+  return b;
+}
+
+int primitiveSemantics_return_imm_reg_06(int a, int b) {
+  return a == 0 ? 1 : b;
+}
+
+int primitiveSemantics_return_imm_reg_07(int a, int b) {
+  return a != 0 ? 1 : b;
+}
+
+int primitiveSemantics_return_imm_reg_08(int a, int b) {
+  return a == 0 ? b : 1;
+}
+
+int primitiveSemantics_return_imm_reg_09(int a, int b) {
+  return a != 0 ? b : 1;
+}
+
+int primitiveSemantics_return_imm_reg_10(int a, int b) {
+  if (a)
+    b = 1;
+  return b;
+}
+
+int primitiveSemantics_return_imm_reg_11(int a, int b) {
+  if (!a)
+    b = 1;
+  return b;
+}
+
+/* { dg-final { scan-assembler-times "czero.eqz" 6 } } */
+/* { dg-final { scan-assembler-times "czero.nez" 6 } } */
+/* { dg-final { scan-assembler-not "beq" } } */
+/* { dg-final { scan-assembler-not "bne" } } */
diff --git a/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_reg_reg.c b/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_reg_reg.c
new file mode 100644
index 00000000000..4708afa645b
--- /dev/null
+++ b/gcc/testsuite/gcc.target/riscv/zicond-primitiveSemantics_return_reg_reg.c
@@ -0,0 +1,65 @@ 
+/* { dg-do compile } */
+/* { dg-options "-march=rv64gc_zicond -mabi=lp64d" { target { rv64 } } } */
+/* { dg-options "-march=rv32gc_zicond -mabi=ilp32f" { target { rv32 } } } */
+/* { dg-skip-if "" { *-*-* } {"-O0" "-Os"} } */
+
+long primitiveSemantics_return_reg_reg_00(long a, long b, long c) {
+  return a == 0 ? c : b;
+}
+
+long primitiveSemantics_return_reg_reg_01(long a, long b, long c) {
+  return a != 0 ? c : b;
+}
+
+long primitiveSemantics_return_reg_reg_02(long a, long b, long c) {
+  return a == 0 ? b : c;
+}
+
+long primitiveSemantics_return_reg_reg_03(long a, long b, long c) {
+  return a != 0 ? b : c;
+}
+
+long primitiveSemantics_return_reg_reg_04(long a, long b, long c) {
+  if (a)
+    b = c;
+  return b;
+}
+
+long primitiveSemantics_return_reg_reg_05(long a, long b, long c) {
+  if (!a)
+    b = c;
+  return b;
+}
+
+int primitiveSemantics_return_reg_reg_06(int a, int b, int c) {
+  return a == 0 ? c : b;
+}
+
+int primitiveSemantics_return_reg_reg_07(int a, int b, int c) {
+  return a != 0 ? c : b;
+}
+
+int primitiveSemantics_return_reg_reg_08(int a, int b, int c) {
+  return a == 0 ? b : c;
+}
+
+int primitiveSemantics_return_reg_reg_09(int a, int b, int c) {
+  return a != 0 ? b : c;
+}
+
+int primitiveSemantics_return_reg_reg_10(int a, int b, int c) {
+  if (a)
+    b = c;
+  return b;
+}
+
+int primitiveSemantics_return_reg_reg_11(int a, int b, int c) {
+  if (!a)
+    b = c;
+  return b;
+}
+
+/* { dg-final { scan-assembler-times "czero.eqz" 12 } } */
+/* { dg-final { scan-assembler-times "czero.nez" 12 } } */
+/* { dg-final { scan-assembler-not "beq" } } */
+/* { dg-final { scan-assembler-not "bne" } } */