diff options
| -rw-r--r-- | llvm/lib/CodeGen/CodeGenPrepare.cpp | 14 | ||||
| -rw-r--r-- | llvm/test/Transforms/CodeGenPrepare/X86/fcmp-sinking.ll | 29 |
2 files changed, 38 insertions, 5 deletions
diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp index 8ba52c424a6..afd37a0efe7 100644 --- a/llvm/lib/CodeGen/CodeGenPrepare.cpp +++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp @@ -855,10 +855,14 @@ static bool CombineUAddWithOverflow(CmpInst *CI) { /// lose; some adjustment may be wanted there. /// /// Return true if any changes are made. -static bool SinkCmpExpression(CmpInst *CI) { +static bool SinkCmpExpression(CmpInst *CI, const TargetLowering &TLI) { BasicBlock *DefBB = CI->getParent(); - /// Only insert a cmp in each block once. + // Avoid sinking soft-FP comparisons, since this can move them into a loop. + if (TLI.useSoftFloat() && isa<FCmpInst>(CI)) + return false; + + // Only insert a cmp in each block once. DenseMap<BasicBlock*, CmpInst*> InsertedCmps; bool MadeChange = false; @@ -906,8 +910,8 @@ static bool SinkCmpExpression(CmpInst *CI) { return MadeChange; } -static bool OptimizeCmpExpression(CmpInst *CI) { - if (SinkCmpExpression(CI)) +static bool OptimizeCmpExpression(CmpInst *CI, const TargetLowering &TLI) { + if (SinkCmpExpression(CI, TLI)) return true; if (CombineUAddWithOverflow(CI)) @@ -5173,7 +5177,7 @@ bool CodeGenPrepare::optimizeInst(Instruction *I, bool& ModifiedDT) { if (CmpInst *CI = dyn_cast<CmpInst>(I)) if (!TLI || !TLI->hasMultipleConditionRegisters()) - return OptimizeCmpExpression(CI); + return OptimizeCmpExpression(CI, *TLI); if (LoadInst *LI = dyn_cast<LoadInst>(I)) { stripInvariantGroupMetadata(*LI); diff --git a/llvm/test/Transforms/CodeGenPrepare/X86/fcmp-sinking.ll b/llvm/test/Transforms/CodeGenPrepare/X86/fcmp-sinking.ll new file mode 100644 index 00000000000..94ab74f9e7b --- /dev/null +++ b/llvm/test/Transforms/CodeGenPrepare/X86/fcmp-sinking.ll @@ -0,0 +1,29 @@ +; RUN: opt %s -codegenprepare -mattr=+soft-float -S | FileCheck %s -check-prefix=CHECK -check-prefix=SOFTFP +; RUN: opt %s -codegenprepare -mattr=-soft-float -S | FileCheck %s -check-prefix=CHECK -check-prefix=HARDFP + +target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +; CHECK-LABEL: @foo +; CHECK: entry: +; SOFTFP: fcmp +; HARDFP-NOT: fcmp +; CHECK: body: +; SOFTFP-NOT: fcmp +; HARDFP: fcmp +define void @foo(float %a, float %b) { +entry: + %c = fcmp oeq float %a, %b + br label %head +head: + %IND = phi i32 [ 0, %entry ], [ %IND.new, %body1 ] + %CMP = icmp slt i32 %IND, 1250 + br i1 %CMP, label %body, label %tail +body: + br i1 %c, label %body1, label %tail +body1: + %IND.new = add i32 %IND, 1 + br label %head +tail: + ret void +} |
