Author: Jay Foad Date: 2021-01-14T18:15:17Z New Revision: 868da2ea939baf8c71a6dcb878cf6094ede9486e
URL: https://github.com/llvm/llvm-project/commit/868da2ea939baf8c71a6dcb878cf6094ede9486e DIFF: https://github.com/llvm/llvm-project/commit/868da2ea939baf8c71a6dcb878cf6094ede9486e.diff LOG: [SelectionDAG] Remove an early-out from computeKnownBits for smin/smax Even if we know nothing about LHS, it can still be useful to know that smax(LHS, RHS) >= RHS and smin(LHS, RHS) <= RHS. Differential Revision: https://reviews.llvm.org/D87145 Added: Modified: llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp llvm/test/CodeGen/X86/known-bits-vector.ll Removed: ################################################################################ diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 7084ab68524b5..82da553954d2f 100644 --- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -3416,7 +3416,6 @@ KnownBits SelectionDAG::computeKnownBits(SDValue Op, const APInt &DemandedElts, } 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); diff --git a/llvm/test/CodeGen/X86/known-bits-vector.ll b/llvm/test/CodeGen/X86/known-bits-vector.ll index 3b6912a9d9461..05bf984101abc 100644 --- a/llvm/test/CodeGen/X86/known-bits-vector.ll +++ b/llvm/test/CodeGen/X86/known-bits-vector.ll @@ -435,11 +435,7 @@ define <4 x float> @knownbits_smax_smin_shuffle_uitofp(<4 x i32> %a0) { ; 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 @@ define <4 x float> @knownbits_smax_smin_shuffle_uitofp(<4 x i32> %a0) { ; 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>) _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
