[04/44] RISC-V: Sanitise NEED_EQ_NE_P case with `riscv_emit_int_compare'

Message ID alpine.DEB.2.20.2311171401210.5892@tpp.orcam.me.uk
State Accepted
Headers
Series RISC-V: Various if-conversion fixes and improvements |

Checks

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

Commit Message

Maciej W. Rozycki Nov. 19, 2023, 5:36 a.m. UTC
  For the NEED_EQ_NE_P `riscv_emit_int_compare' is documented to only emit 
EQ or NE comparisons against zero, however it does not catch incorrect 
use where a non-equality comparison has been requested and falls through 
to the general case then.  Add a safety guard to catch such a case then.

Arguably the NEED_EQ_NE_P case would best be moved into a function of 
its own, but let's leave it for a separate cleanup.

	gcc/
	* config/riscv/riscv.cc (riscv_emit_int_compare): Bail out if
	NEED_EQ_NE_P but the comparison is neither EQ nor NE.	
---
FWIW the structure of code here clearly shows the NEED_EQ_NE_P case has 
been bolted on as an afterthought rather than how this piece would look 
if written from scratch right away.  Let's defer any further cleanups at 
this stage of the development cycle though.
---
 gcc/config/riscv/riscv.cc |    1 +
 1 file changed, 1 insertion(+)

gcc-riscv-emit-int-compare-need-eq-ne.diff
  

Patch

Index: gcc/gcc/config/riscv/riscv.cc
===================================================================
--- gcc.orig/gcc/config/riscv/riscv.cc
+++ gcc/gcc/config/riscv/riscv.cc
@@ -3779,6 +3779,7 @@  riscv_emit_int_compare (enum rtx_code *c
 	  *op1 = const0_rtx;
 	  return;
 	}
+      gcc_unreachable ();
     }
 
   if (splittable_const_int_operand (*op1, VOIDmode))