diff options
| -rw-r--r-- | llvm/test/Transforms/LoopStrengthReduce/AArch64/small-constant.ll | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/llvm/test/Transforms/LoopStrengthReduce/AArch64/small-constant.ll b/llvm/test/Transforms/LoopStrengthReduce/AArch64/small-constant.ll new file mode 100644 index 00000000000..585759dd178 --- /dev/null +++ b/llvm/test/Transforms/LoopStrengthReduce/AArch64/small-constant.ll @@ -0,0 +1,151 @@ +; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py + +; RUN: llc < %s -mtriple=aarch64-unknown-unknown | FileCheck %s + +; LSR doesn't consider bumping a pointer by constants outside the loop when the +; constants fit as immediate add operands. The constants are re-associated as an +; unfolded offset rather than a register and are not combined later with +; loop-invariant registers. For large-enough constants LSR produces better +; solutions for these test cases, with test1 switching from: +; +; The chosen solution requires 2 instructions 2 regs, with addrec cost 1, plus 1 scale cost, plus 4 imm cost, plus 1 setup cost: +; LSR Use: Kind=ICmpZero, Offsets={0}, widest fixup type: i64 +; -7 + reg({(7 + %start)<nsw>,+,1}<nsw><%for.body>) +; LSR Use: Kind=Address of float in addrspace(0), Offsets={0}, widest fixup type: float* +; reg(%arr) + 4*reg({(7 + %start)<nsw>,+,1}<nsw><%for.body>) +; +; to: +; +; The chosen solution requires 1 instruction 2 regs, with addrec cost 1, plus 1 scale cost, plus 1 setup cost: +; LSR Use: Kind=ICmpZero, Offsets={0}, widest fixup type: i64 +; reg({%start,+,1}<nsw><%for.body>) +; LSR Use: Kind=Address of float in addrspace(0), Offsets={0}, widest fixup type: float* +; reg((88888 + %arr)) + 4*reg({%start,+,1}<nsw><%for.body>) +; +; and test2 switching from: +; +; The chosen solution requires 2 instructions 2 regs, with addrec cost 1, plus 1 base add, plus 1 scale cost: +; LSR Use: Kind=ICmpZero, Offsets={0}, widest fixup type: i64 +; reg({%start,+,1}<nsw><%for.body>) +; LSR Use: Kind=Basic, Offsets={0}, widest fixup type: i64 +; reg({%start,+,1}<nsw><%for.body>) +; LSR Use: Kind=Address of float in addrspace(0), Offsets={0}, widest fixup type: float* +; reg(%arr) + 4*reg({%start,+,1}<nsw><%for.body>) + imm(28) +; +; to: +; +; The chosen solution requires 1 instruction 2 regs, with addrec cost 1, plus 1 scale cost, plus 1 setup cost: +; LSR Use: Kind=ICmpZero, Offsets={0}, widest fixup type: i64 +; reg({%start,+,1}<nsw><%for.body>) +; LSR Use: Kind=Basic, Offsets={0}, widest fixup type: i64 +; reg({%start,+,1}<nsw><%for.body>) +; LSR Use: Kind=Address of float in addrspace(0), Offsets={0}, widest fixup type: float* +; reg((88888 + %arr)) + 4*reg({%start,+,1}<nsw><%for.body>) + +; float test(float *arr, long long start, float threshold) { +; for (long long i = start; i != 0; ++i) { +; float x = arr[i + 7]; +; if (x > threshold) +; return x; +; } +; return -7; +; } +define float @test1(float* nocapture readonly %arr, i64 %start, float %threshold) { +; CHECK-LABEL: test1: +; CHECK: // %bb.0: // %entry +; CHECK-NEXT: fmov s2, #-7.00000000 +; CHECK-NEXT: cbz x1, .LBB0_5 +; CHECK-NEXT: // %bb.1: // %for.body.preheader +; CHECK-NEXT: add x8, x1, #7 // =7 +; CHECK-NEXT: .LBB0_2: // %for.body +; CHECK-NEXT: // =>This Inner Loop Header: Depth=1 +; CHECK-NEXT: ldr s1, [x0, x8, lsl #2] +; CHECK-NEXT: fcmp s1, s0 +; CHECK-NEXT: b.gt .LBB0_6 +; CHECK-NEXT: // %bb.3: // %for.cond +; CHECK-NEXT: // in Loop: Header=BB0_2 Depth=1 +; CHECK-NEXT: add x8, x8, #1 // =1 +; CHECK-NEXT: cmp x8, #7 // =7 +; CHECK-NEXT: b.ne .LBB0_2 +; CHECK-NEXT: // %bb.4: +; CHECK-NEXT: mov v0.16b, v2.16b +; CHECK-NEXT: ret +; CHECK-NEXT: .LBB0_5: +; CHECK-NEXT: mov v0.16b, v2.16b +; CHECK-NEXT: ret +; CHECK-NEXT: .LBB0_6: // %cleanup2 +; CHECK-NEXT: mov v0.16b, v1.16b +; CHECK-NEXT: ret +entry: + %cmp11 = icmp eq i64 %start, 0 + br i1 %cmp11, label %cleanup2, label %for.body + +for.cond: ; preds = %for.body + %cmp = icmp eq i64 %inc, 0 + br i1 %cmp, label %cleanup2, label %for.body + +for.body: ; preds = %entry, %for.cond + %i.012 = phi i64 [ %inc, %for.cond ], [ %start, %entry ] + %add = add nsw i64 %i.012, 7 + %arrayidx = getelementptr inbounds float, float* %arr, i64 %add + %0 = load float, float* %arrayidx, align 4 + %cmp1 = fcmp ogt float %0, %threshold + %inc = add nsw i64 %i.012, 1 + br i1 %cmp1, label %cleanup2, label %for.cond + +cleanup2: ; preds = %for.cond, %for.body, %entry + %1 = phi float [ -7.000000e+00, %entry ], [ %0, %for.body ], [ -7.000000e+00, %for.cond ] + ret float %1 +} + +; Same as test1, except i has another use: +; if (x > threshold) ---> if (x > threshold + i) +define float @test2(float* nocapture readonly %arr, i64 %start, float %threshold) { +; CHECK-LABEL: test2: +; CHECK: // %bb.0: // %entry +; CHECK-NEXT: fmov s2, #-7.00000000 +; CHECK-NEXT: cbz x1, .LBB1_4 +; CHECK-NEXT: .LBB1_1: // %for.body +; CHECK-NEXT: // =>This Inner Loop Header: Depth=1 +; CHECK-NEXT: add x8, x0, x1, lsl #2 +; CHECK-NEXT: ldr s1, [x8, #28] +; CHECK-NEXT: scvtf s3, x1 +; CHECK-NEXT: fadd s3, s3, s0 +; CHECK-NEXT: fcmp s1, s3 +; CHECK-NEXT: b.gt .LBB1_5 +; CHECK-NEXT: // %bb.2: // %for.cond +; CHECK-NEXT: // in Loop: Header=BB1_1 Depth=1 +; CHECK-NEXT: add x1, x1, #1 // =1 +; CHECK-NEXT: cbnz x1, .LBB1_1 +; CHECK-NEXT: // %bb.3: +; CHECK-NEXT: mov v0.16b, v2.16b +; CHECK-NEXT: ret +; CHECK-NEXT: .LBB1_4: +; CHECK-NEXT: mov v0.16b, v2.16b +; CHECK-NEXT: ret +; CHECK-NEXT: .LBB1_5: // %cleanup4 +; CHECK-NEXT: mov v0.16b, v1.16b +; CHECK-NEXT: ret +entry: + %cmp14 = icmp eq i64 %start, 0 + br i1 %cmp14, label %cleanup4, label %for.body + +for.cond: ; preds = %for.body + %cmp = icmp eq i64 %inc, 0 + br i1 %cmp, label %cleanup4, label %for.body + +for.body: ; preds = %entry, %for.cond + %i.015 = phi i64 [ %inc, %for.cond ], [ %start, %entry ] + %add = add nsw i64 %i.015, 7 + %arrayidx = getelementptr inbounds float, float* %arr, i64 %add + %0 = load float, float* %arrayidx, align 4 + %conv = sitofp i64 %i.015 to float + %add1 = fadd float %conv, %threshold + %cmp2 = fcmp ogt float %0, %add1 + %inc = add nsw i64 %i.015, 1 + br i1 %cmp2, label %cleanup4, label %for.cond + +cleanup4: ; preds = %for.cond, %for.body, %entry + %1 = phi float [ -7.000000e+00, %entry ], [ %0, %for.body ], [ -7.000000e+00, %for.cond ] + ret float %1 +} |
