diff mbox series

simplify-rtx: Fix up last argument to simplify_gen_unary [PR113656]

Message ID ZboIYMC/12V1YSKi@tucnak
State Unresolved
Headers
Series simplify-rtx: Fix up last argument to simplify_gen_unary [PR113656] |

Checks

Context Check Description
snail/gcc-patch-check warning Git am fail log

Commit Message

Jakub Jelinek Jan. 31, 2024, 8:44 a.m. UTC 
  Hi!

When simplifying e.g. (float_truncate:SF (float_truncate:DF (reg:XF))
or (float_truncate:SF (float_extend:XF (reg:DF)) etc. into
(float_truncate:SF (reg:XF)) or (float_truncate:SF (reg:DF)) we call
simplify_gen_unary with incorrect op_mode argument, it should be
the argument's mode, but we call it with the outer mode instead.
As these are all floating point operations, the argument always
has non-VOIDmode and so we can just use that mode (as done in similar
simplifications a few lines later), but neither FLOAT_TRUNCATE nor
FLOAT_EXTEND are operations that should have the same modes of operand
and result.  This bug hasn't been a problem for years because normally
op_mode is used only if the mode of op is VOIDmode, otherwise it is
redundant, but r10-2139 added an assertion in some spots that op_mode
is right even in such cases.

Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

2024-01-31  Jakub Jelinek  <jakub@redhat.com>

	PR rtl-optimization/113656
	* simplify-rtx.cc (simplify_context::simplify_unary_operation_1)
	<case FLOAT_TRUNCATE>: Fix up last argument to simplify_gen_unary.

	* gcc.target/i386/pr113656.c: New test.


	Jakub

Comments

Richard Biener Jan. 31, 2024, 9:04 a.m. UTC | #1 
On Wed, 31 Jan 2024, Jakub Jelinek wrote:

> Hi!
> 
> When simplifying e.g. (float_truncate:SF (float_truncate:DF (reg:XF))
> or (float_truncate:SF (float_extend:XF (reg:DF)) etc. into
> (float_truncate:SF (reg:XF)) or (float_truncate:SF (reg:DF)) we call
> simplify_gen_unary with incorrect op_mode argument, it should be
> the argument's mode, but we call it with the outer mode instead.
> As these are all floating point operations, the argument always
> has non-VOIDmode and so we can just use that mode (as done in similar
> simplifications a few lines later), but neither FLOAT_TRUNCATE nor
> FLOAT_EXTEND are operations that should have the same modes of operand
> and result.  This bug hasn't been a problem for years because normally
> op_mode is used only if the mode of op is VOIDmode, otherwise it is
> redundant, but r10-2139 added an assertion in some spots that op_mode
> is right even in such cases.
> 
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?

OK.

> 2024-01-31  Jakub Jelinek  <jakub@redhat.com>
> 
> 	PR rtl-optimization/113656
> 	* simplify-rtx.cc (simplify_context::simplify_unary_operation_1)
> 	<case FLOAT_TRUNCATE>: Fix up last argument to simplify_gen_unary.
> 
> 	* gcc.target/i386/pr113656.c: New test.
> 
> --- gcc/simplify-rtx.cc.jj	2024-01-03 11:51:32.828713189 +0100
> +++ gcc/simplify-rtx.cc	2024-01-30 19:34:30.516934480 +0100
> @@ -1305,7 +1305,7 @@ simplify_context::simplify_unary_operati
>  	  			   > GET_MODE_UNIT_SIZE (mode)
>  	  			   ? FLOAT_TRUNCATE : FLOAT_EXTEND,
>  				   mode,
> -				   XEXP (op, 0), mode);
> +				   XEXP (op, 0), GET_MODE (XEXP (op, 0)));
>  
>        /*  (float_truncate (float x)) is (float x)  */
>        if ((GET_CODE (op) == FLOAT || GET_CODE (op) == UNSIGNED_FLOAT)
> --- gcc/testsuite/gcc.target/i386/pr113656.c.jj	2024-01-30 19:38:29.029608721 +0100
> +++ gcc/testsuite/gcc.target/i386/pr113656.c	2024-01-30 19:37:10.519703443 +0100
> @@ -0,0 +1,12 @@
> +/* PR rtl-optimization/113656 */
> +/* { dg-do compile } */
> +/* { dg-options "-O3 -frounding-math -funsafe-math-optimizations -mavx512fp16 -mavx512vl" } */
> +
> +_Float16 a[8];
> +
> +void
> +foo ()
> +{
> +  for (int i = 0; i < 8; i++)
> +    a[i] = i - 8.4;
> +}
> 
> 	Jakub
> 
>
diff mbox series

Patch

--- gcc/simplify-rtx.cc.jj	2024-01-03 11:51:32.828713189 +0100
+++ gcc/simplify-rtx.cc	2024-01-30 19:34:30.516934480 +0100
@@ -1305,7 +1305,7 @@  simplify_context::simplify_unary_operati
 	  			   > GET_MODE_UNIT_SIZE (mode)
 	  			   ? FLOAT_TRUNCATE : FLOAT_EXTEND,
 				   mode,
-				   XEXP (op, 0), mode);
+				   XEXP (op, 0), GET_MODE (XEXP (op, 0)));
 
       /*  (float_truncate (float x)) is (float x)  */
       if ((GET_CODE (op) == FLOAT || GET_CODE (op) == UNSIGNED_FLOAT)
--- gcc/testsuite/gcc.target/i386/pr113656.c.jj	2024-01-30 19:38:29.029608721 +0100
+++ gcc/testsuite/gcc.target/i386/pr113656.c	2024-01-30 19:37:10.519703443 +0100
@@ -0,0 +1,12 @@ 
+/* PR rtl-optimization/113656 */
+/* { dg-do compile } */
+/* { dg-options "-O3 -frounding-math -funsafe-math-optimizations -mavx512fp16 -mavx512vl" } */
+
+_Float16 a[8];
+
+void
+foo ()
+{
+  for (int i = 0; i < 8; i++)
+    a[i] = i - 8.4;
+}