[gcc(refs/vendors/riscv/heads/ext-dce)] Remove hack that should no longer be needed.

[gcc(refs/vendors/riscv/heads/ext-dce)] Remove hack that should no longer be needed.

[Jeff Law]

https://gcc.gnu.org/g:4dd02a734d373d6ea558b0fa223a1ca769a9e8dd

commit 4dd02a734d373d6ea558b0fa223a1ca769a9e8dd
Author: Jeff Law <jlaw@ventanamicro.com>
Date:   Wed Nov 15 12:03:48 2023 -0700

    Remove hack that should no longer be needed.

Diff:
---
 gcc/ext-dce.cc | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/gcc/ext-dce.cc b/gcc/ext-dce.cc
index 9cf0a3c2ae3..64f6885d484 100644
--- a/gcc/ext-dce.cc
+++ b/gcc/ext-dce.cc
@@ -395,18 +395,6 @@ ext_dce_process_uses (rtx_insn *insn, bitmap livenow, bitmap live_tmp,
 		  unsigned HOST_WIDE_INT src_mask
 		    = GET_MODE_MASK (GET_MODE (inner));
 
-#if 0
-		  /* ?!? This seems like it shouldn't be necessary.  */
-		  /* Pretend there is one additional higher bit set in
-		     MASK2 to account for the sign bit propagation from the
-		     input value into the output value.  */
-		  if (code == SIGN_EXTEND)
-		    {
-		      src_mask <<= 1;
-		      src_mask |= 1;
-		    }
-#endif
-
 		  /* (subreg (mem)) is technically valid RTL, but is
 		     severely discouraged.  So give up if we're about to
 		     create one.