[llvm-branch-commits] [SPARC] Promote i32 CTTZ when we have VIS3 (PR #135894)

[via llvm-branch-commits]

================
@@ -1,70 +1,195 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
-; RUN: llc < %s -mtriple=sparc -mcpu=v9 | FileCheck %s
+; RUN: llc < %s -mtriple=sparcv9 | FileCheck %s -check-prefix=V9
+; RUN: llc < %s -mtriple=sparcv9 -mattr=popc | FileCheck %s -check-prefix=POPC
+; RUN: llc < %s -mtriple=sparcv9 -mattr=vis3 | FileCheck %s -check-prefix=VIS3
 
-define i32 @f(i32 %x) {
-; CHECK-LABEL: f:
-; CHECK:         .cfi_startproc
-; CHECK-NEXT:  ! %bb.0: ! %entry
-; CHECK-NEXT:    sub %g0, %o0, %o1
-; CHECK-NEXT:    and %o0, %o1, %o1
-; CHECK-NEXT:    sethi 122669, %o2
-; CHECK-NEXT:    or %o2, 305, %o2
-; CHECK-NEXT:    smul %o1, %o2, %o1
-; CHECK-NEXT:    srl %o1, 27, %o1
-; CHECK-NEXT:    sethi %hi(.LCPI0_0), %o2
-; CHECK-NEXT:    add %o2, %lo(.LCPI0_0), %o2
-; CHECK-NEXT:    ldub [%o2+%o1], %o1
-; CHECK-NEXT:    cmp %o0, 0
-; CHECK-NEXT:    move %icc, 0, %o1
-; CHECK-NEXT:    retl
-; CHECK-NEXT:    mov %o1, %o0
-entry:
-  %0 = call i32 @llvm.cttz.i32(i32 %x, i1 true)
-  %1 = icmp eq i32 %x, 0
-  %2 = select i1 %1, i32 0, i32 %0
-  %3 = trunc i32 %2 to i8
-  %conv = zext i8 %3 to i32
-  ret i32 %conv
+define i32 @i32_nopoison(i32 %x) nounwind {
+; V9-LABEL: i32_nopoison:
+; V9:       ! %bb.0:
+; V9-NEXT:    cmp %o0, 0
+; V9-NEXT:    be %icc, .LBB0_2
+; V9-NEXT:    nop
+; V9-NEXT:  ! %bb.1: ! %cond.false
+; V9-NEXT:    sub %g0, %o0, %o1
+; V9-NEXT:    and %o0, %o1, %o0
+; V9-NEXT:    sethi 122669, %o1
+; V9-NEXT:    or %o1, 305, %o1
+; V9-NEXT:    mulx %o0, %o1, %o0
+; V9-NEXT:    srl %o0, 27, %o0
+; V9-NEXT:    srl %o0, 0, %o0
+; V9-NEXT:    sethi %h44(.LCPI0_0), %o1
+; V9-NEXT:    add %o1, %m44(.LCPI0_0), %o1
+; V9-NEXT:    sllx %o1, 12, %o1
+; V9-NEXT:    add %o1, %l44(.LCPI0_0), %o1
+; V9-NEXT:    retl
+; V9-NEXT:    ldub [%o1+%o0], %o0
+; V9-NEXT:  .LBB0_2:
+; V9-NEXT:    retl
+; V9-NEXT:    mov 32, %o0
----------------
koachan wrote:

So unfortunately setting CTTZ and/or CTTZ_ZERO_UNDEF to LibCall results in a crash like those:
```
LLVM ERROR: Cannot select: t3: i32 = cttz_zero_undef t2
  t2: i32,ch = CopyFromReg t0, Register:i32 %0
    t1: i32 = Register %0
In function: i32_nopoison
```
I'll just FIXME them for the time being, I think.

https://github.com/llvm/llvm-project/pull/135894