Allow PeepholeOptimizer to fold a few more cases

The condition for clearing the folding candidate list was clamped together
with the "uninteresting instruction" condition. This is too conservative,
e.g. we don't need to clear the list when encountering an IMPLICIT_DEF.

Differential Revision: http://reviews.llvm.org/D11591

llvm-svn: 244577

diff --git a/llvm/lib/CodeGen/PeepholeOptimizer.cpp b/llvm/lib/CodeGen/PeepholeOptimizer.cpp
index 21d603b..3dc73ba 100644 (file)
--- a/llvm/lib/CodeGen/PeepholeOptimizer.cpp
+++ b/llvm/lib/CodeGen/PeepholeOptimizer.cpp
@@ -1236,14 +1236,13 @@ bool PeepholeOptimizer::runOnMachineFunction(MachineFunction &MF) {
 
       // If there exists an instruction which belongs to the following
       // categories, we will discard the load candidates.
+      if (MI->mayStore() || MI->isCall() || MI->hasUnmodeledSideEffects())
+        FoldAsLoadDefCandidates.clear();
+
       if (MI->isPosition() || MI->isPHI() || MI->isImplicitDef() ||
           MI->isKill() || MI->isInlineAsm() ||
-          MI->hasUnmodeledSideEffects()) {
-        FoldAsLoadDefCandidates.clear();
+          MI->hasUnmodeledSideEffects())
         continue;
-      }
-      if (MI->mayStore() || MI->isCall())
-        FoldAsLoadDefCandidates.clear();
 
       if ((isUncoalescableCopy(*MI) &&
            optimizeUncoalescableCopy(MI, LocalMIs)) ||

diff --git a/llvm/test/CodeGen/X86/avx-cvt.ll b/llvm/test/CodeGen/X86/avx-cvt.ll
index 6df3e53..2f03986 100644 (file)
--- a/llvm/test/CodeGen/X86/avx-cvt.ll
+++ b/llvm/test/CodeGen/X86/avx-cvt.ll
@@ -113,8 +113,7 @@ define float @funcD(i64* nocapture %e) nounwind uwtable readonly ssp {
 define void @fpext() nounwind uwtable {
 ; CHECK-LABEL: fpext:
 ; CHECK:       # BB#0:
-; CHECK-NEXT:    vmovss {{.*#+}} xmm0 = mem[0],zero,zero,zero
-; CHECK-NEXT:    vcvtss2sd %xmm0, %xmm0, %xmm0
+; CHECK-NEXT:    vcvtss2sd -{{[0-9]+}}(%rsp), %xmm0, %xmm0
 ; CHECK-NEXT:    vmovsd %xmm0, -{{[0-9]+}}(%rsp)
 ; CHECK-NEXT:    retq
   %f = alloca float, align 4

diff --git a/llvm/test/CodeGen/X86/shift-bmi2.ll b/llvm/test/CodeGen/X86/shift-bmi2.ll
index 63b6ec5..fdeddff 100644 (file)
--- a/llvm/test/CodeGen/X86/shift-bmi2.ll
+++ b/llvm/test/CodeGen/X86/shift-bmi2.ll
@@ -30,11 +30,10 @@ entry:
   %x = load i32, i32* %p
   %shl = shl i32 %x, %shamt
 ; BMI2: shl32p
-; Source order scheduling prevents folding, rdar:14208996.
-; BMI2: shlxl %{{.+}}, %{{.+}}, %{{.+}}
+; BMI2: shlxl %{{.+}}, ({{.+}}), %{{.+}}
 ; BMI2: ret
 ; BMI264: shl32p
-; BMI264: shlxl %{{.+}}, %{{.+}}, %{{.+}}
+; BMI264: shlxl %{{.+}}, ({{.+}}), %{{.+}}
 ; BMI264: ret
   ret i32 %shl
 }
@@ -75,7 +74,7 @@ entry:
   %x = load i64, i64* %p
   %shl = shl i64 %x, %shamt
 ; BMI264: shl64p
-; BMI264: shlxq %{{.+}}, %{{.+}}, %{{.+}}
+; BMI264: shlxq %{{.+}}, ({{.+}}), %{{.+}}
 ; BMI264: ret
   ret i64 %shl
 }
@@ -107,11 +106,10 @@ entry:
   %x = load i32, i32* %p
   %shl = lshr i32 %x, %shamt
 ; BMI2: lshr32p
-; Source order scheduling prevents folding, rdar:14208996.
-; BMI2: shrxl %{{.+}}, %{{.+}}, %{{.+}}
+; BMI2: shrxl %{{.+}}, ({{.+}}), %{{.+}}
 ; BMI2: ret
 ; BMI264: lshr32p
-; BMI264: shrxl %{{.+}}, %{{.+}}, %{{.+}}
+; BMI264: shrxl %{{.+}}, ({{.+}}), %{{.+}}
 ; BMI264: ret
   ret i32 %shl
 }
@@ -130,7 +128,7 @@ entry:
   %x = load i64, i64* %p
   %shl = lshr i64 %x, %shamt
 ; BMI264: lshr64p
-; BMI264: shrxq %{{.+}}, %{{.+}}, %{{.+}}
+; BMI264: shrxq %{{.+}}, ({{.+}}), %{{.+}}
 ; BMI264: ret
   ret i64 %shl
 }
@@ -153,10 +151,10 @@ entry:
   %shl = ashr i32 %x, %shamt
 ; BMI2: ashr32p
 ; Source order scheduling prevents folding, rdar:14208996.
-; BMI2: sarxl %{{.+}}, %{{.+}}, %{{.+}}
+; BMI2: sarxl %{{.+}}, ({{.+}}), %{{.+}}
 ; BMI2: ret
 ; BMI264: ashr32p
-; BMI264: sarxl %{{.+}}, %{{.+}}, %{{.+}}
+; BMI264: sarxl %{{.+}}, ({{.+}}), %{{.+}}
 ; BMI264: ret
   ret i32 %shl
 }
@@ -175,7 +173,7 @@ entry:
   %x = load i64, i64* %p
   %shl = ashr i64 %x, %shamt
 ; BMI264: ashr64p
-; BMI264: sarxq %{{.+}}, %{{.+}}, %{{.+}}
+; BMI264: sarxq %{{.+}}, ({{.+}}), %{{.+}}
 ; BMI264: ret
   ret i64 %shl
 }