[llvm] [RISCV][GISel] Remove s32 support for G_CTPOP/CTLZ/CTTZ on RV64. (PR #115101)

[Craig Topper via llvm-commits]

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@@ -794,6 +792,8 @@ define signext i32 @ctpop_i32_load(ptr %p) nounwind {
 ; RV64ZBB-LABEL: ctpop_i32_load:
 ; RV64ZBB:       # %bb.0:
 ; RV64ZBB-NEXT:    lw a0, 0(a0)
+; RV64ZBB-NEXT:    slli a0, a0, 32
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topperc wrote:

It's not needed. The two shifts are a zero_extend from s32 to s64. We need to enable load+zext combine post legalization to get rid of the zext.

https://github.com/llvm/llvm-project/pull/115101