[X86] Enable combineExtSetcc for vectors larger than 256 bits when we've disabled...

The compares are going to be type legalized to 256 bits so we
might as well fold the extend.

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index eba4db9..ec1040e 100644 (file)
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -44762,7 +44762,7 @@ static SDValue combineExtSetcc(SDNode *N, SelectionDAG &DAG,
 
   // We can only do this if the vector size in 256 bits or less.
   unsigned Size = VT.getSizeInBits();
-  if (Size > 256)
+  if (Size > 256 && Subtarget.useAVX512Regs())
     return SDValue();
 
   // Don't fold if the condition code can't be handled by PCMPEQ/PCMPGT since

diff --git a/llvm/test/CodeGen/X86/min-legal-vector-width.ll b/llvm/test/CodeGen/X86/min-legal-vector-width.ll
index 44ed303..81de0ee 100644 (file)
--- a/llvm/test/CodeGen/X86/min-legal-vector-width.ll
+++ b/llvm/test/CodeGen/X86/min-legal-vector-width.ll
@@ -1600,3 +1600,43 @@ define i32 @v64i1_inline_asm() "min-legal-vector-width"="256" {
   %4 = load i32, i32* %1, align 4
   ret i32 %4
 }
+
+define void @cmp_v8i64_sext(<8 x i64>* %xptr, <8 x i64>* %yptr, <8 x i64>* %zptr) "min-legal-vector-width"="256" {
+; CHECK-LABEL: cmp_v8i64_sext:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    vmovdqa (%rsi), %ymm0
+; CHECK-NEXT:    vmovdqa 32(%rsi), %ymm1
+; CHECK-NEXT:    vpcmpgtq 32(%rdi), %ymm1, %ymm1
+; CHECK-NEXT:    vpcmpgtq (%rdi), %ymm0, %ymm0
+; CHECK-NEXT:    vmovdqa %ymm0, (%rdx)
+; CHECK-NEXT:    vmovdqa %ymm1, 32(%rdx)
+; CHECK-NEXT:    vzeroupper
+; CHECK-NEXT:    retq
+  %x = load <8 x i64>, <8 x i64>* %xptr
+  %y = load <8 x i64>, <8 x i64>* %yptr
+  %cmp = icmp slt <8 x i64> %x, %y
+  %ext = sext <8 x i1> %cmp to <8 x i64>
+  store <8 x i64> %ext, <8 x i64>* %zptr
+  ret void
+}
+
+define void @cmp_v8i64_zext(<8 x i64>* %xptr, <8 x i64>* %yptr, <8 x i64>* %zptr) "min-legal-vector-width"="256" {
+; CHECK-LABEL: cmp_v8i64_zext:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    vmovdqa (%rsi), %ymm0
+; CHECK-NEXT:    vmovdqa 32(%rsi), %ymm1
+; CHECK-NEXT:    vpcmpgtq 32(%rdi), %ymm1, %ymm1
+; CHECK-NEXT:    vpcmpgtq (%rdi), %ymm0, %ymm0
+; CHECK-NEXT:    vpsrlq $63, %ymm1, %ymm1
+; CHECK-NEXT:    vpsrlq $63, %ymm0, %ymm0
+; CHECK-NEXT:    vmovdqa %ymm0, (%rdx)
+; CHECK-NEXT:    vmovdqa %ymm1, 32(%rdx)
+; CHECK-NEXT:    vzeroupper
+; CHECK-NEXT:    retq
+  %x = load <8 x i64>, <8 x i64>* %xptr
+  %y = load <8 x i64>, <8 x i64>* %yptr
+  %cmp = icmp slt <8 x i64> %x, %y
+  %ext = zext <8 x i1> %cmp to <8 x i64>
+  store <8 x i64> %ext, <8 x i64>* %zptr
+  ret void
+}