[LoopStrengthReduce] add test to show potential macro-fusion-based diff (PR35681); NFC

This is the baseline output for the test proposed with D42607.

llvm-svn: 323806

1 files changed, 126 insertions, 0 deletions

diff --git a/llvm/test/Transforms/LoopStrengthReduce/X86/macro-fuse-cmp.ll b/llvm/test/Transforms/LoopStrengthReduce/X86/macro-fuse-cmp.ll
new file mode 100644
index 00000000000..b1909ed3299
--- /dev/null
+++ b/llvm/test/Transforms/LoopStrengthReduce/X86/macro-fuse-cmp.ll
@@ -0,0 +1,126 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: opt < %s -loop-reduce -mcpu=btver2  -S | FileCheck %s --check-prefix=JAG
+; RUN: opt < %s -loop-reduce -mcpu=haswell -S | FileCheck %s --check-prefix=HSW
+
+; RUN: llc < %s                    | FileCheck %s --check-prefix=BASE
+; RUN: llc < %s -mattr=macrofusion | FileCheck %s --check-prefix=FUSE
+
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-unknown-unknown"
+
+; PR35681 - https://bugs.llvm.org/show_bug.cgi?id=35681
+; FIXME: If a CPU can macro-fuse a compare and branch, then we discount that
+; cost in LSR and avoid generating large offsets in each memory access.
+; This reduces code size and may improve decode throughput.
+
+define void @maxArray(double* noalias nocapture %x, double* noalias nocapture readonly %y) {
+; JAG-LABEL: @maxArray(
+; JAG-NEXT:  entry:
+; JAG-NEXT:    [[Y1:%.*]] = bitcast double* [[Y:%.*]] to <2 x double>*
+; JAG-NEXT:    [[X4:%.*]] = bitcast double* [[X:%.*]] to <2 x double>*
+; JAG-NEXT:    [[X45:%.*]] = bitcast <2 x double>* [[X4]] to i8*
+; JAG-NEXT:    [[Y12:%.*]] = bitcast <2 x double>* [[Y1]] to i8*
+; JAG-NEXT:    br label [[VECTOR_BODY:%.*]]
+; JAG:       vector.body:
+; JAG-NEXT:    [[LSR_IV:%.*]] = phi i64 [ [[LSR_IV_NEXT:%.*]], [[VECTOR_BODY]] ], [ -524288, [[ENTRY:%.*]] ]
+; JAG-NEXT:    [[UGLYGEP9:%.*]] = getelementptr i8, i8* [[X45]], i64 [[LSR_IV]]
+; JAG-NEXT:    [[UGLYGEP910:%.*]] = bitcast i8* [[UGLYGEP9]] to <2 x double>*
+; JAG-NEXT:    [[SCEVGEP11:%.*]] = getelementptr <2 x double>, <2 x double>* [[UGLYGEP910]], i64 32768
+; JAG-NEXT:    [[UGLYGEP:%.*]] = getelementptr i8, i8* [[Y12]], i64 [[LSR_IV]]
+; JAG-NEXT:    [[UGLYGEP3:%.*]] = bitcast i8* [[UGLYGEP]] to <2 x double>*
+; JAG-NEXT:    [[SCEVGEP:%.*]] = getelementptr <2 x double>, <2 x double>* [[UGLYGEP3]], i64 32768
+; JAG-NEXT:    [[XVAL:%.*]] = load <2 x double>, <2 x double>* [[SCEVGEP11]], align 8
+; JAG-NEXT:    [[YVAL:%.*]] = load <2 x double>, <2 x double>* [[SCEVGEP]], align 8
+; JAG-NEXT:    [[CMP:%.*]] = fcmp ogt <2 x double> [[YVAL]], [[XVAL]]
+; JAG-NEXT:    [[MAX:%.*]] = select <2 x i1> [[CMP]], <2 x double> [[YVAL]], <2 x double> [[XVAL]]
+; JAG-NEXT:    [[UGLYGEP6:%.*]] = getelementptr i8, i8* [[X45]], i64 [[LSR_IV]]
+; JAG-NEXT:    [[UGLYGEP67:%.*]] = bitcast i8* [[UGLYGEP6]] to <2 x double>*
+; JAG-NEXT:    [[SCEVGEP8:%.*]] = getelementptr <2 x double>, <2 x double>* [[UGLYGEP67]], i64 32768
+; JAG-NEXT:    store <2 x double> [[MAX]], <2 x double>* [[SCEVGEP8]], align 8
+; JAG-NEXT:    [[LSR_IV_NEXT]] = add nsw i64 [[LSR_IV]], 16
+; JAG-NEXT:    [[DONE:%.*]] = icmp eq i64 [[LSR_IV_NEXT]], 0
+; JAG-NEXT:    br i1 [[DONE]], label [[EXIT:%.*]], label [[VECTOR_BODY]]
+; JAG:       exit:
+; JAG-NEXT:    ret void
+;
+; HSW-LABEL: @maxArray(
+; HSW-NEXT:  entry:
+; HSW-NEXT:    [[Y1:%.*]] = bitcast double* [[Y:%.*]] to <2 x double>*
+; HSW-NEXT:    [[X4:%.*]] = bitcast double* [[X:%.*]] to <2 x double>*
+; HSW-NEXT:    [[X45:%.*]] = bitcast <2 x double>* [[X4]] to i8*
+; HSW-NEXT:    [[Y12:%.*]] = bitcast <2 x double>* [[Y1]] to i8*
+; HSW-NEXT:    br label [[VECTOR_BODY:%.*]]
+; HSW:       vector.body:
+; HSW-NEXT:    [[LSR_IV:%.*]] = phi i64 [ [[LSR_IV_NEXT:%.*]], [[VECTOR_BODY]] ], [ -524288, [[ENTRY:%.*]] ]
+; HSW-NEXT:    [[UGLYGEP9:%.*]] = getelementptr i8, i8* [[X45]], i64 [[LSR_IV]]
+; HSW-NEXT:    [[UGLYGEP910:%.*]] = bitcast i8* [[UGLYGEP9]] to <2 x double>*
+; HSW-NEXT:    [[SCEVGEP11:%.*]] = getelementptr <2 x double>, <2 x double>* [[UGLYGEP910]], i64 32768
+; HSW-NEXT:    [[UGLYGEP:%.*]] = getelementptr i8, i8* [[Y12]], i64 [[LSR_IV]]
+; HSW-NEXT:    [[UGLYGEP3:%.*]] = bitcast i8* [[UGLYGEP]] to <2 x double>*
+; HSW-NEXT:    [[SCEVGEP:%.*]] = getelementptr <2 x double>, <2 x double>* [[UGLYGEP3]], i64 32768
+; HSW-NEXT:    [[XVAL:%.*]] = load <2 x double>, <2 x double>* [[SCEVGEP11]], align 8
+; HSW-NEXT:    [[YVAL:%.*]] = load <2 x double>, <2 x double>* [[SCEVGEP]], align 8
+; HSW-NEXT:    [[CMP:%.*]] = fcmp ogt <2 x double> [[YVAL]], [[XVAL]]
+; HSW-NEXT:    [[MAX:%.*]] = select <2 x i1> [[CMP]], <2 x double> [[YVAL]], <2 x double> [[XVAL]]
+; HSW-NEXT:    [[UGLYGEP6:%.*]] = getelementptr i8, i8* [[X45]], i64 [[LSR_IV]]
+; HSW-NEXT:    [[UGLYGEP67:%.*]] = bitcast i8* [[UGLYGEP6]] to <2 x double>*
+; HSW-NEXT:    [[SCEVGEP8:%.*]] = getelementptr <2 x double>, <2 x double>* [[UGLYGEP67]], i64 32768
+; HSW-NEXT:    store <2 x double> [[MAX]], <2 x double>* [[SCEVGEP8]], align 8
+; HSW-NEXT:    [[LSR_IV_NEXT]] = add nsw i64 [[LSR_IV]], 16
+; HSW-NEXT:    [[DONE:%.*]] = icmp eq i64 [[LSR_IV_NEXT]], 0
+; HSW-NEXT:    br i1 [[DONE]], label [[EXIT:%.*]], label [[VECTOR_BODY]]
+; HSW:       exit:
+; HSW-NEXT:    ret void
+;
+; BASE-LABEL: maxArray:
+; BASE:       # %bb.0: # %entry
+; BASE-NEXT:    movq $-524288, %rax # imm = 0xFFF80000
+; BASE-NEXT:    .p2align 4, 0x90
+; BASE-NEXT:  .LBB0_1: # %vector.body
+; BASE-NEXT:    # =>This Inner Loop Header: Depth=1
+; BASE-NEXT:    movupd 524288(%rdi,%rax), %xmm0
+; BASE-NEXT:    movupd 524288(%rsi,%rax), %xmm1
+; BASE-NEXT:    maxpd %xmm0, %xmm1
+; BASE-NEXT:    movupd %xmm1, 524288(%rdi,%rax)
+; BASE-NEXT:    addq $16, %rax
+; BASE-NEXT:    jne .LBB0_1
+; BASE-NEXT:  # %bb.2: # %exit
+; BASE-NEXT:    retq
+;
+; FUSE-LABEL: maxArray:
+; FUSE:       # %bb.0: # %entry
+; FUSE-NEXT:    movq $-524288, %rax # imm = 0xFFF80000
+; FUSE-NEXT:    .p2align 4, 0x90
+; FUSE-NEXT:  .LBB0_1: # %vector.body
+; FUSE-NEXT:    # =>This Inner Loop Header: Depth=1
+; FUSE-NEXT:    movupd 524288(%rdi,%rax), %xmm0
+; FUSE-NEXT:    movupd 524288(%rsi,%rax), %xmm1
+; FUSE-NEXT:    maxpd %xmm0, %xmm1
+; FUSE-NEXT:    movupd %xmm1, 524288(%rdi,%rax)
+; FUSE-NEXT:    addq $16, %rax
+; FUSE-NEXT:    jne .LBB0_1
+; FUSE-NEXT:  # %bb.2: # %exit
+; FUSE-NEXT:    retq
+entry:
+  br label %vector.body
+
+vector.body:
+  %index = phi i64 [ 0, %entry ], [ %index.next, %vector.body ]
+  %gepx = getelementptr inbounds double, double* %x, i64 %index
+  %gepy = getelementptr inbounds double, double* %y, i64 %index
+  %xptr = bitcast double* %gepx to <2 x double>*
+  %yptr = bitcast double* %gepy to <2 x double>*
+  %xval = load <2 x double>, <2 x double>* %xptr, align 8
+  %yval = load <2 x double>, <2 x double>* %yptr, align 8
+  %cmp = fcmp ogt <2 x double> %yval, %xval
+  %max = select <2 x i1> %cmp, <2 x double> %yval, <2 x double> %xval
+  %xptr_again = bitcast double* %gepx to <2 x double>*
+  store <2 x double> %max, <2 x double>* %xptr_again, align 8
+  %index.next = add i64 %index, 2
+  %done = icmp eq i64 %index.next, 65536
+  br i1 %done, label %exit, label %vector.body
+
+exit:
+  ret void
+}
+