diff options
| -rw-r--r-- | llvm/lib/Transforms/Scalar/DivRemPairs.cpp | 6 | ||||
| -rw-r--r-- | llvm/test/Other/X86/debugcounter-divrempairs.ll | 91 |
2 files changed, 97 insertions, 0 deletions
diff --git a/llvm/lib/Transforms/Scalar/DivRemPairs.cpp b/llvm/lib/Transforms/Scalar/DivRemPairs.cpp index e1bc590c5c9..ffcf34f1cf7 100644 --- a/llvm/lib/Transforms/Scalar/DivRemPairs.cpp +++ b/llvm/lib/Transforms/Scalar/DivRemPairs.cpp @@ -21,6 +21,7 @@ #include "llvm/IR/Dominators.h" #include "llvm/IR/Function.h" #include "llvm/Pass.h" +#include "llvm/Support/DebugCounter.h" #include "llvm/Transforms/Scalar.h" #include "llvm/Transforms/Utils/BypassSlowDivision.h" using namespace llvm; @@ -29,6 +30,8 @@ using namespace llvm; STATISTIC(NumPairs, "Number of div/rem pairs"); STATISTIC(NumHoisted, "Number of instructions hoisted"); STATISTIC(NumDecomposed, "Number of instructions decomposed"); +DEBUG_COUNTER(DRPCounter, "div-rem-pairs-transform", + "Controls transformations in div-rem-pairs pass"); /// Find matching pairs of integer div/rem ops (they have the same numerator, /// denominator, and signedness). If they exist in different basic blocks, bring @@ -93,6 +96,9 @@ static bool optimizeDivRem(Function &F, const TargetTransformInfo &TTI, if (!DivDominates && !DT.dominates(RemInst, DivInst)) continue; + if (!DebugCounter::shouldExecute(DRPCounter)) + continue; + if (HasDivRemOp) { // The target has a single div/rem operation. Hoist the lower instruction // to make the matched pair visible to the backend. diff --git a/llvm/test/Other/X86/debugcounter-divrempairs.ll b/llvm/test/Other/X86/debugcounter-divrempairs.ll new file mode 100644 index 00000000000..4b787e9d2e7 --- /dev/null +++ b/llvm/test/Other/X86/debugcounter-divrempairs.ll @@ -0,0 +1,91 @@ +; REQUIRES: asserts +; RUN: opt < %s -div-rem-pairs -debug-counter=div-rem-pairs-transform-skip=1,div-rem-pairs-transform-count=1 \ +; RUN: -S -mtriple=x86_64-unknown-unknown | FileCheck %s +;; Test that, with debug counters on, we only skip the first div-rem-pairs opportunity, optimize one after it, +;; and then ignore all the others. There is 1 optimization opportunity in f1, 2 in f2, and another 1 in f3, +;; only the first one in f2 will be performed. + +define i64 @f1(i64 %a, i64 %b) { +; CHECK-LABEL: @f1( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[REM:%.*]] = urem i64 %a, %b +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i64 [[REM]], 42 +; CHECK-NEXT: br i1 [[CMP]], label %if, label %end +; CHECK: if: +; CHECK-NEXT: [[DIV:%.*]] = udiv i64 %a, %b +; CHECK-NEXT: br label %end +; CHECK: end: +; CHECK-NEXT: [[RET:%.*]] = phi i64 [ [[DIV]], %if ], [ 3, %entry ] +; CHECK-NEXT: ret i64 [[RET]] +; +entry: + %rem = urem i64 %a, %b + %cmp = icmp eq i64 %rem, 42 + br i1 %cmp, label %if, label %end + +if: + %div = udiv i64 %a, %b + br label %end + +end: + %ret = phi i64 [ %div, %if ], [ 3, %entry ] + ret i64 %ret +} + +define i16 @f2(i16 %a, i16 %b) { +; CHECK-LABEL: @f2( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[DIV1:%.*]] = sdiv i16 %a, %b +; CHECK-NEXT: [[REM1:%.*]] = srem i16 %a, %b +; CHECK-NEXT: [[DIV2:%.*]] = udiv i16 %a, %b +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i16 [[DIV1]], 42 +; CHECK-NEXT: br i1 [[CMP]], label %if, label %end +; CHECK: if: +; CHECK-NEXT: [[REM2:%.*]] = urem i16 %a, %b +; CHECK-NEXT: br label %end +; CHECK: end: +; CHECK-NEXT: [[RET:%.*]] = phi i16 [ [[REM1]], %if ], [ 3, %entry ] +; CHECK-NEXT: ret i16 [[RET]] +; +entry: + %div1 = sdiv i16 %a, %b + %div2 = udiv i16 %a, %b + %cmp = icmp eq i16 %div1, 42 + br i1 %cmp, label %if, label %end + +if: + %rem1 = srem i16 %a, %b + %rem2 = urem i16 %a, %b + br label %end + +end: + %ret = phi i16 [ %rem1, %if ], [ 3, %entry ] + ret i16 %ret +} + +define i32 @f3(i32 %a, i32 %b) { +; CHECK-LABEL: @f3( +; CHECK-NEXT: entry: +; CHECK-NEXT: [[REM:%.*]] = srem i32 %a, %b +; CHECK-NEXT: [[CMP:%.*]] = icmp eq i32 [[REM]], 42 +; CHECK-NEXT: br i1 [[CMP]], label %if, label %end +; CHECK: if: +; CHECK-NEXT: [[DIV:%.*]] = sdiv i32 %a, %b +; CHECK-NEXT: br label %end +; CHECK: end: +; CHECK-NEXT: [[RET:%.*]] = phi i32 [ [[DIV]], %if ], [ 3, %entry ] +; CHECK-NEXT: ret i32 [[RET]] +; +entry: + %rem = srem i32 %a, %b + %cmp = icmp eq i32 %rem, 42 + br i1 %cmp, label %if, label %end + +if: + %div = sdiv i32 %a, %b + br label %end + +end: + %ret = phi i32 [ %div, %if ], [ 3, %entry ] + ret i32 %ret +}
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