[PATCH] D87145: [SelectionDAG] Remove an early-out from computeKnownBits for smin/smax

[Jay Foad via Phabricator via llvm-commits]

foad updated this revision to Diff 316697.
foad added a comment.

Rebase.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D87145/new/

https://reviews.llvm.org/D87145

Files:
  llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
  llvm/test/CodeGen/X86/known-bits-vector.ll


Index: llvm/test/CodeGen/X86/known-bits-vector.ll
===================================================================
--- llvm/test/CodeGen/X86/known-bits-vector.ll
+++ llvm/test/CodeGen/X86/known-bits-vector.ll
@@ -435,11 +435,7 @@
 ; X32-NEXT:    vpminsd {{\.LCPI.*}}, %xmm0, %xmm0
 ; X32-NEXT:    vpmaxsd {{\.LCPI.*}}, %xmm0, %xmm0
 ; X32-NEXT:    vpshufd {{.*#+}} xmm0 = xmm0[0,0,3,3]
-; X32-NEXT:    vpblendw {{.*#+}} xmm1 = xmm0[0],mem[1],xmm0[2],mem[3],xmm0[4],mem[5],xmm0[6],mem[7]
-; X32-NEXT:    vpsrld $16, %xmm0, %xmm0
-; X32-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],mem[1],xmm0[2],mem[3],xmm0[4],mem[5],xmm0[6],mem[7]
-; X32-NEXT:    vsubps {{\.LCPI.*}}, %xmm0, %xmm0
-; X32-NEXT:    vaddps %xmm0, %xmm1, %xmm0
+; X32-NEXT:    vcvtdq2ps %xmm0, %xmm0
 ; X32-NEXT:    retl
 ;
 ; X64-LABEL: knownbits_smax_smin_shuffle_uitofp:
@@ -447,11 +443,7 @@
 ; X64-NEXT:    vpminsd {{.*}}(%rip), %xmm0, %xmm0
 ; X64-NEXT:    vpmaxsd {{.*}}(%rip), %xmm0, %xmm0
 ; X64-NEXT:    vpshufd {{.*#+}} xmm0 = xmm0[0,0,3,3]
-; X64-NEXT:    vpblendw {{.*#+}} xmm1 = xmm0[0],mem[1],xmm0[2],mem[3],xmm0[4],mem[5],xmm0[6],mem[7]
-; X64-NEXT:    vpsrld $16, %xmm0, %xmm0
-; X64-NEXT:    vpblendw {{.*#+}} xmm0 = xmm0[0],mem[1],xmm0[2],mem[3],xmm0[4],mem[5],xmm0[6],mem[7]
-; X64-NEXT:    vsubps {{.*}}(%rip), %xmm0, %xmm0
-; X64-NEXT:    vaddps %xmm0, %xmm1, %xmm0
+; X64-NEXT:    vcvtdq2ps %xmm0, %xmm0
 ; X64-NEXT:    retq
   %1 = call <4 x i32> @llvm.x86.sse41.pminsd(<4 x i32> %a0, <4 x i32> <i32 0, i32 -65535, i32 -65535, i32 0>)
   %2 = call <4 x i32> @llvm.x86.sse41.pmaxsd(<4 x i32> %1, <4 x i32> <i32 65535, i32 -1, i32 -1, i32 131071>)
Index: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
===================================================================
--- llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -3416,7 +3416,6 @@
     }
 
     Known = computeKnownBits(Op.getOperand(0), DemandedElts, Depth + 1);
-    if (Known.isUnknown()) break; // Early-out
     Known2 = computeKnownBits(Op.getOperand(1), DemandedElts, Depth + 1);
     if (IsMax)
       Known = KnownBits::smax(Known, Known2);


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