https://gcc.gnu.org/g:3514d03e8ba53f76b672baf7935b0258ac9609b5
commit 3514d03e8ba53f76b672baf7935b0258ac9609b5
Author: Jeff Law <j...@ventanamicro.com>
Date: Sun Jul 21 08:41:28 2024 -0600
[PR rtl-optimization/115877][2/n] Improve liveness computation for constant
initialization
While debugging pr115877, I noticed we were failing to remove the
destination
register from LIVENOW bitmap when it was set to a constant value. ie (set
(dest) (const_int)). This was a trivial oversight in
safe_for_live_propagation.
I don't have an example of this affecting code generation, but it certainly
could. More importantly, by making LIVENOW more accurate it's easier to
debug
when LIVENOW differs from expectations.
As with the prior patch this has been tested as part of a larger patchset
with
the crosses as well as individually on x86_64.
Pushing to the trunk,
PR rtl-optimization/115877
gcc/
* ext-dce.cc (safe_for_live_propagation): Handle RTX_CONST_OBJ.
Diff:
---
gcc/ext-dce.cc | 1 +
1 file changed, 1 insertion(+)
diff --git a/gcc/ext-dce.cc b/gcc/ext-dce.cc
index b4450e42ed16..cbecfc53dba7 100644
--- a/gcc/ext-dce.cc
+++ b/gcc/ext-dce.cc
@@ -69,6 +69,7 @@ safe_for_live_propagation (rtx_code code)
switch (GET_RTX_CLASS (code))
{
case RTX_OBJ:
+ case RTX_CONST_OBJ:
return true;
case RTX_COMPARE:
