[InstCombine] Revert the signed icmp -> unsigned icmp canonicalization when folding icmp Pred min|max(X, Y), Z
#76685
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@llvm/pr-subscribers-llvm-transforms Author: Yingwei Zheng (dtcxzyw) ChangesThis patch tries to flip the signedness of predicates when folding an unsigned icmp with a signed min/max. It will enable more optimizations as we canonicalizes a signed icmp into an unsigned icmp when both operands are known to have the same sign. Compile-time impact: http://llvm-compile-time-tracker.com/compare.php?from=949ec83eaf6fa6dbffb94c2ea9c0a4d5efdbd239&to=2deca1aea8a4e13609bab72c522a97d424f0fc2d&stat=instructions:u
NOTE: We can flip the signedness of predicate if both operands are negative. But I don't see the benefit of handling these cases. BTW, should we add a flag like Patch is 75.67 KiB, truncated to 20.00 KiB below, full version: https://github.com/llvm/llvm-project/pull/76685.diff 14 Files Affected:
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 54d74905b960ef..320f174f077860 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -5047,8 +5047,16 @@ InstCombinerImpl::foldICmpWithMinMaxImpl(Instruction &I,
Value *Y = MinMax->getRHS();
if (ICmpInst::isSigned(Pred) && !MinMax->isSigned())
return nullptr;
- if (ICmpInst::isUnsigned(Pred) && MinMax->isSigned())
- return nullptr;
+ if (ICmpInst::isUnsigned(Pred) && MinMax->isSigned()) {
+ // Revert the transform signed pred -> unsigned pred
+ // TODO: We can flip the signedness of predicate if both operands of icmp
+ // are negative.
+ if (isKnownNonNegative(Z, SQ.getWithInstruction(&I)) &&
+ isKnownNonNegative(MinMax, SQ.getWithInstruction(&I))) {
+ Pred = ICmpInst::getFlippedSignednessPredicate(Pred);
+ } else
+ return nullptr;
+ }
SimplifyQuery Q = SQ.getWithInstruction(&I);
auto IsCondKnownTrue = [](Value *Val) -> std::optional<bool> {
if (!Val)
diff --git a/llvm/test/Transforms/InstCombine/smax-icmp.ll b/llvm/test/Transforms/InstCombine/smax-icmp.ll
index 0ccbef34889fda..022ec6ad4f3466 100644
--- a/llvm/test/Transforms/InstCombine/smax-icmp.ll
+++ b/llvm/test/Transforms/InstCombine/smax-icmp.ll
@@ -804,4 +804,45 @@ end:
ret void
}
+; Tests from PR76672
+
+define i1 @test_smax_ugt(i32 %a) {
+; CHECK-LABEL: @test_smax_ugt(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[CMP:%.*]] = icmp sgt i32 [[A:%.*]], 1
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+entry:
+ %cond.i = call i32 @llvm.smax.i32(i32 %a, i32 0)
+ %cmp = icmp ugt i32 %cond.i, 1
+ ret i1 %cmp
+}
+
+; Negative tests
+
+define i1 @test_smax_ugt_neg1(i32 %a) {
+; CHECK-LABEL: @test_smax_ugt_neg1(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: ret i1 false
+;
+entry:
+ %cond.i = call i32 @llvm.smax.i32(i32 %a, i32 0)
+ %cmp = icmp ugt i32 %cond.i, -5
+ ret i1 %cmp
+}
+
+define i1 @test_smax_ugt_neg2(i32 %a) {
+; CHECK-LABEL: @test_smax_ugt_neg2(
+; CHECK-NEXT: entry:
+; CHECK-NEXT: [[COND_I:%.*]] = call i32 @llvm.smax.i32(i32 [[A:%.*]], i32 -5)
+; CHECK-NEXT: [[CMP:%.*]] = icmp ugt i32 [[COND_I]], 1
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+entry:
+ %cond.i = call i32 @llvm.smax.i32(i32 %a, i32 -5)
+ %cmp = icmp ugt i32 %cond.i, 1
+ ret i1 %cmp
+}
+
+
declare i32 @llvm.smax.i32(i32, i32)
diff --git a/llvm/test/Transforms/LoopVectorize/X86/float-induction-x86.ll b/llvm/test/Transforms/LoopVectorize/X86/float-induction-x86.ll
index fb87228a9ff987..184f510f5ab8de 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/float-induction-x86.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/float-induction-x86.ll
@@ -197,7 +197,7 @@ define double @external_use_with_fast_math(ptr %a, i64 %n) {
; AUTO_VEC-LABEL: @external_use_with_fast_math(
; AUTO_VEC-NEXT: entry:
; AUTO_VEC-NEXT: [[SMAX:%.*]] = tail call i64 @llvm.smax.i64(i64 [[N:%.*]], i64 1)
-; AUTO_VEC-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[SMAX]], 16
+; AUTO_VEC-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp slt i64 [[N]], 16
; AUTO_VEC-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[FOR_BODY:%.*]], label [[VECTOR_PH:%.*]]
; AUTO_VEC: vector.ph:
; AUTO_VEC-NEXT: [[N_VEC:%.*]] = and i64 [[SMAX]], 9223372036854775792
@@ -264,7 +264,7 @@ define double @external_use_without_fast_math(ptr %a, i64 %n) {
; AUTO_VEC-NEXT: entry:
; AUTO_VEC-NEXT: [[SMAX:%.*]] = tail call i64 @llvm.smax.i64(i64 [[N:%.*]], i64 1)
; AUTO_VEC-NEXT: [[XTRAITER:%.*]] = and i64 [[SMAX]], 7
-; AUTO_VEC-NEXT: [[TMP0:%.*]] = icmp ult i64 [[SMAX]], 8
+; AUTO_VEC-NEXT: [[TMP0:%.*]] = icmp slt i64 [[N]], 8
; AUTO_VEC-NEXT: br i1 [[TMP0]], label [[FOR_END_UNR_LCSSA:%.*]], label [[ENTRY_NEW:%.*]]
; AUTO_VEC: entry.new:
; AUTO_VEC-NEXT: [[UNROLL_ITER:%.*]] = and i64 [[SMAX]], 9223372036854775800
diff --git a/llvm/test/Transforms/LoopVectorize/X86/invariant-load-gather.ll b/llvm/test/Transforms/LoopVectorize/X86/invariant-load-gather.ll
index 9b432de35c9d11..8783326b1ef1af 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/invariant-load-gather.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/invariant-load-gather.ll
@@ -9,19 +9,18 @@ define i32 @inv_load_conditional(ptr %a, i64 %n, ptr %b, i32 %k) {
; CHECK-NEXT: iter.check:
; CHECK-NEXT: [[NTRUNC:%.*]] = trunc i64 [[N:%.*]] to i32
; CHECK-NEXT: [[SMAX2:%.*]] = call i64 @llvm.smax.i64(i64 [[N]], i64 1)
-; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[SMAX2]], 8
+; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp slt i64 [[N]], 8
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[VEC_EPILOG_SCALAR_PH:%.*]], label [[VECTOR_MEMCHECK:%.*]]
; CHECK: vector.memcheck:
-; CHECK-NEXT: [[SMAX:%.*]] = call i64 @llvm.smax.i64(i64 [[N]], i64 1)
-; CHECK-NEXT: [[TMP0:%.*]] = shl i64 [[SMAX]], 2
-; CHECK-NEXT: [[UGLYGEP:%.*]] = getelementptr i8, ptr [[B:%.*]], i64 [[TMP0]]
-; CHECK-NEXT: [[UGLYGEP1:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 4
-; CHECK-NEXT: [[BOUND0:%.*]] = icmp ugt ptr [[UGLYGEP1]], [[B]]
-; CHECK-NEXT: [[BOUND1:%.*]] = icmp ugt ptr [[UGLYGEP]], [[A]]
+; CHECK-NEXT: [[TMP0:%.*]] = shl i64 [[N]], 2
+; CHECK-NEXT: [[SCEVGEP:%.*]] = getelementptr i8, ptr [[B:%.*]], i64 [[TMP0]]
+; CHECK-NEXT: [[SCEVGEP1:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 4
+; CHECK-NEXT: [[BOUND0:%.*]] = icmp ugt ptr [[SCEVGEP1]], [[B]]
+; CHECK-NEXT: [[BOUND1:%.*]] = icmp ugt ptr [[SCEVGEP]], [[A]]
; CHECK-NEXT: [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
; CHECK-NEXT: br i1 [[FOUND_CONFLICT]], label [[VEC_EPILOG_SCALAR_PH]], label [[VECTOR_MAIN_LOOP_ITER_CHECK:%.*]]
; CHECK: vector.main.loop.iter.check:
-; CHECK-NEXT: [[MIN_ITERS_CHECK3:%.*]] = icmp ult i64 [[SMAX2]], 16
+; CHECK-NEXT: [[MIN_ITERS_CHECK3:%.*]] = icmp slt i64 [[N]], 16
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK3]], label [[VEC_EPILOG_PH:%.*]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: [[N_VEC:%.*]] = and i64 [[SMAX2]], 9223372036854775792
@@ -33,13 +32,13 @@ define i32 @inv_load_conditional(ptr %a, i64 %n, ptr %b, i32 %k) {
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP1:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[INDEX]]
-; CHECK-NEXT: store <16 x i32> [[BROADCAST_SPLAT5]], ptr [[TMP1]], align 4, !alias.scope !0, !noalias !3
+; CHECK-NEXT: store <16 x i32> [[BROADCAST_SPLAT5]], ptr [[TMP1]], align 4, !alias.scope [[META0:![0-9]+]], !noalias [[META3:![0-9]+]]
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 16
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
; CHECK-NEXT: br i1 [[TMP2]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP5:![0-9]+]]
; CHECK: middle.block:
; CHECK-NEXT: [[TMP3:%.*]] = icmp ne <16 x ptr> [[BROADCAST_SPLAT]], zeroinitializer
-; CHECK-NEXT: [[WIDE_MASKED_GATHER:%.*]] = call <16 x i32> @llvm.masked.gather.v16i32.v16p0(<16 x ptr> [[BROADCAST_SPLAT]], i32 4, <16 x i1> [[TMP3]], <16 x i32> poison), !alias.scope !3
+; CHECK-NEXT: [[WIDE_MASKED_GATHER:%.*]] = call <16 x i32> @llvm.masked.gather.v16i32.v16p0(<16 x ptr> [[BROADCAST_SPLAT]], i32 4, <16 x i1> [[TMP3]], <16 x i32> poison), !alias.scope [[META3]]
; CHECK-NEXT: [[PREDPHI:%.*]] = select <16 x i1> [[TMP3]], <16 x i32> [[WIDE_MASKED_GATHER]], <16 x i32> <i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 1>
; CHECK-NEXT: [[TMP4:%.*]] = extractelement <16 x i32> [[PREDPHI]], i64 15
; CHECK-NEXT: [[CMP_N:%.*]] = icmp eq i64 [[SMAX2]], [[N_VEC]]
@@ -51,23 +50,23 @@ define i32 @inv_load_conditional(ptr %a, i64 %n, ptr %b, i32 %k) {
; CHECK: vec.epilog.ph:
; CHECK-NEXT: [[VEC_EPILOG_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[VEC_EPILOG_ITER_CHECK]] ], [ 0, [[VECTOR_MAIN_LOOP_ITER_CHECK]] ]
; CHECK-NEXT: [[N_VEC7:%.*]] = and i64 [[SMAX2]], 9223372036854775800
-; CHECK-NEXT: [[BROADCAST_SPLATINSERT11:%.*]] = insertelement <8 x ptr> poison, ptr [[A]], i64 0
-; CHECK-NEXT: [[BROADCAST_SPLAT12:%.*]] = shufflevector <8 x ptr> [[BROADCAST_SPLATINSERT11]], <8 x ptr> poison, <8 x i32> zeroinitializer
-; CHECK-NEXT: [[BROADCAST_SPLATINSERT13:%.*]] = insertelement <8 x i32> poison, i32 [[NTRUNC]], i64 0
-; CHECK-NEXT: [[BROADCAST_SPLAT14:%.*]] = shufflevector <8 x i32> [[BROADCAST_SPLATINSERT13]], <8 x i32> poison, <8 x i32> zeroinitializer
+; CHECK-NEXT: [[BROADCAST_SPLATINSERT10:%.*]] = insertelement <8 x ptr> poison, ptr [[A]], i64 0
+; CHECK-NEXT: [[BROADCAST_SPLAT11:%.*]] = shufflevector <8 x ptr> [[BROADCAST_SPLATINSERT10]], <8 x ptr> poison, <8 x i32> zeroinitializer
+; CHECK-NEXT: [[BROADCAST_SPLATINSERT12:%.*]] = insertelement <8 x i32> poison, i32 [[NTRUNC]], i64 0
+; CHECK-NEXT: [[BROADCAST_SPLAT13:%.*]] = shufflevector <8 x i32> [[BROADCAST_SPLATINSERT12]], <8 x i32> poison, <8 x i32> zeroinitializer
; CHECK-NEXT: br label [[VEC_EPILOG_VECTOR_BODY:%.*]]
; CHECK: vec.epilog.vector.body:
-; CHECK-NEXT: [[INDEX9:%.*]] = phi i64 [ [[VEC_EPILOG_RESUME_VAL]], [[VEC_EPILOG_PH]] ], [ [[INDEX_NEXT17:%.*]], [[VEC_EPILOG_VECTOR_BODY]] ]
+; CHECK-NEXT: [[INDEX9:%.*]] = phi i64 [ [[VEC_EPILOG_RESUME_VAL]], [[VEC_EPILOG_PH]] ], [ [[INDEX_NEXT16:%.*]], [[VEC_EPILOG_VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP5:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[INDEX9]]
-; CHECK-NEXT: store <8 x i32> [[BROADCAST_SPLAT14]], ptr [[TMP5]], align 4, !alias.scope !8, !noalias !11
-; CHECK-NEXT: [[INDEX_NEXT17]] = add nuw i64 [[INDEX9]], 8
-; CHECK-NEXT: [[TMP6:%.*]] = icmp eq i64 [[INDEX_NEXT17]], [[N_VEC7]]
+; CHECK-NEXT: store <8 x i32> [[BROADCAST_SPLAT13]], ptr [[TMP5]], align 4, !alias.scope [[META8:![0-9]+]], !noalias [[META11:![0-9]+]]
+; CHECK-NEXT: [[INDEX_NEXT16]] = add nuw i64 [[INDEX9]], 8
+; CHECK-NEXT: [[TMP6:%.*]] = icmp eq i64 [[INDEX_NEXT16]], [[N_VEC7]]
; CHECK-NEXT: br i1 [[TMP6]], label [[VEC_EPILOG_MIDDLE_BLOCK:%.*]], label [[VEC_EPILOG_VECTOR_BODY]], !llvm.loop [[LOOP13:![0-9]+]]
; CHECK: vec.epilog.middle.block:
-; CHECK-NEXT: [[TMP7:%.*]] = icmp ne <8 x ptr> [[BROADCAST_SPLAT12]], zeroinitializer
-; CHECK-NEXT: [[WIDE_MASKED_GATHER15:%.*]] = call <8 x i32> @llvm.masked.gather.v8i32.v8p0(<8 x ptr> [[BROADCAST_SPLAT12]], i32 4, <8 x i1> [[TMP7]], <8 x i32> poison), !alias.scope !11
-; CHECK-NEXT: [[PREDPHI16:%.*]] = select <8 x i1> [[TMP7]], <8 x i32> [[WIDE_MASKED_GATHER15]], <8 x i32> <i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 1>
-; CHECK-NEXT: [[TMP8:%.*]] = extractelement <8 x i32> [[PREDPHI16]], i64 7
+; CHECK-NEXT: [[TMP7:%.*]] = icmp ne <8 x ptr> [[BROADCAST_SPLAT11]], zeroinitializer
+; CHECK-NEXT: [[WIDE_MASKED_GATHER14:%.*]] = call <8 x i32> @llvm.masked.gather.v8i32.v8p0(<8 x ptr> [[BROADCAST_SPLAT11]], i32 4, <8 x i1> [[TMP7]], <8 x i32> poison), !alias.scope [[META11]]
+; CHECK-NEXT: [[PREDPHI15:%.*]] = select <8 x i1> [[TMP7]], <8 x i32> [[WIDE_MASKED_GATHER14]], <8 x i32> <i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 poison, i32 1>
+; CHECK-NEXT: [[TMP8:%.*]] = extractelement <8 x i32> [[PREDPHI15]], i64 7
; CHECK-NEXT: [[CMP_N8:%.*]] = icmp eq i64 [[SMAX2]], [[N_VEC7]]
; CHECK-NEXT: br i1 [[CMP_N8]], label [[FOR_END]], label [[VEC_EPILOG_SCALAR_PH]]
; CHECK: vec.epilog.scalar.ph:
diff --git a/llvm/test/Transforms/LoopVectorize/X86/invariant-store-vectorization.ll b/llvm/test/Transforms/LoopVectorize/X86/invariant-store-vectorization.ll
index 995973a645233d..27f8fbde5f49ab 100644
--- a/llvm/test/Transforms/LoopVectorize/X86/invariant-store-vectorization.ll
+++ b/llvm/test/Transforms/LoopVectorize/X86/invariant-store-vectorization.ll
@@ -12,19 +12,18 @@ define i32 @inv_val_store_to_inv_address_with_reduction(ptr %a, i64 %n, ptr %b)
; CHECK-NEXT: iter.check:
; CHECK-NEXT: [[NTRUNC:%.*]] = trunc i64 [[N:%.*]] to i32
; CHECK-NEXT: [[SMAX2:%.*]] = call i64 @llvm.smax.i64(i64 [[N]], i64 1)
-; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[SMAX2]], 8
+; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp slt i64 [[N]], 8
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[VEC_EPILOG_SCALAR_PH:%.*]], label [[VECTOR_MEMCHECK:%.*]]
; CHECK: vector.memcheck:
; CHECK-NEXT: [[SCEVGEP:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 4
-; CHECK-NEXT: [[SMAX:%.*]] = call i64 @llvm.smax.i64(i64 [[N]], i64 1)
-; CHECK-NEXT: [[TMP0:%.*]] = shl i64 [[SMAX]], 2
+; CHECK-NEXT: [[TMP0:%.*]] = shl i64 [[N]], 2
; CHECK-NEXT: [[SCEVGEP1:%.*]] = getelementptr i8, ptr [[B:%.*]], i64 [[TMP0]]
; CHECK-NEXT: [[BOUND0:%.*]] = icmp ugt ptr [[SCEVGEP1]], [[A]]
; CHECK-NEXT: [[BOUND1:%.*]] = icmp ugt ptr [[SCEVGEP]], [[B]]
; CHECK-NEXT: [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
; CHECK-NEXT: br i1 [[FOUND_CONFLICT]], label [[VEC_EPILOG_SCALAR_PH]], label [[VECTOR_MAIN_LOOP_ITER_CHECK:%.*]]
; CHECK: vector.main.loop.iter.check:
-; CHECK-NEXT: [[MIN_ITERS_CHECK3:%.*]] = icmp ult i64 [[SMAX2]], 64
+; CHECK-NEXT: [[MIN_ITERS_CHECK3:%.*]] = icmp slt i64 [[N]], 64
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK3]], label [[VEC_EPILOG_PH:%.*]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: [[N_VEC:%.*]] = and i64 [[SMAX2]], 9223372036854775744
@@ -36,18 +35,18 @@ define i32 @inv_val_store_to_inv_address_with_reduction(ptr %a, i64 %n, ptr %b)
; CHECK-NEXT: [[VEC_PHI5:%.*]] = phi <16 x i32> [ zeroinitializer, [[VECTOR_PH]] ], [ [[TMP7:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI6:%.*]] = phi <16 x i32> [ zeroinitializer, [[VECTOR_PH]] ], [ [[TMP8:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP1:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[INDEX]]
-; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <16 x i32>, ptr [[TMP1]], align 8, !alias.scope !0
+; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <16 x i32>, ptr [[TMP1]], align 8, !alias.scope [[META0:![0-9]+]]
; CHECK-NEXT: [[TMP2:%.*]] = getelementptr inbounds i32, ptr [[TMP1]], i64 16
-; CHECK-NEXT: [[WIDE_LOAD7:%.*]] = load <16 x i32>, ptr [[TMP2]], align 8, !alias.scope !0
+; CHECK-NEXT: [[WIDE_LOAD7:%.*]] = load <16 x i32>, ptr [[TMP2]], align 8, !alias.scope [[META0]]
; CHECK-NEXT: [[TMP3:%.*]] = getelementptr inbounds i32, ptr [[TMP1]], i64 32
-; CHECK-NEXT: [[WIDE_LOAD8:%.*]] = load <16 x i32>, ptr [[TMP3]], align 8, !alias.scope !0
+; CHECK-NEXT: [[WIDE_LOAD8:%.*]] = load <16 x i32>, ptr [[TMP3]], align 8, !alias.scope [[META0]]
; CHECK-NEXT: [[TMP4:%.*]] = getelementptr inbounds i32, ptr [[TMP1]], i64 48
-; CHECK-NEXT: [[WIDE_LOAD9:%.*]] = load <16 x i32>, ptr [[TMP4]], align 8, !alias.scope !0
+; CHECK-NEXT: [[WIDE_LOAD9:%.*]] = load <16 x i32>, ptr [[TMP4]], align 8, !alias.scope [[META0]]
; CHECK-NEXT: [[TMP5]] = add <16 x i32> [[VEC_PHI]], [[WIDE_LOAD]]
; CHECK-NEXT: [[TMP6]] = add <16 x i32> [[VEC_PHI4]], [[WIDE_LOAD7]]
; CHECK-NEXT: [[TMP7]] = add <16 x i32> [[VEC_PHI5]], [[WIDE_LOAD8]]
; CHECK-NEXT: [[TMP8]] = add <16 x i32> [[VEC_PHI6]], [[WIDE_LOAD9]]
-; CHECK-NEXT: store i32 [[NTRUNC]], ptr [[A]], align 4, !alias.scope !3, !noalias !0
+; CHECK-NEXT: store i32 [[NTRUNC]], ptr [[A]], align 4, !alias.scope [[META3:![0-9]+]], !noalias [[META0]]
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 64
; CHECK-NEXT: [[TMP9:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
; CHECK-NEXT: br i1 [[TMP9]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP5:![0-9]+]]
@@ -72,9 +71,9 @@ define i32 @inv_val_store_to_inv_address_with_reduction(ptr %a, i64 %n, ptr %b)
; CHECK-NEXT: [[INDEX15:%.*]] = phi i64 [ [[VEC_EPILOG_RESUME_VAL]], [[VEC_EPILOG_PH]] ], [ [[INDEX_NEXT18:%.*]], [[VEC_EPILOG_VECTOR_BODY]] ]
; CHECK-NEXT: [[VEC_PHI16:%.*]] = phi <8 x i32> [ [[TMP11]], [[VEC_EPILOG_PH]] ], [ [[TMP13:%.*]], [[VEC_EPILOG_VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP12:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[INDEX15]]
-; CHECK-NEXT: [[WIDE_LOAD17:%.*]] = load <8 x i32>, ptr [[TMP12]], align 8, !alias.scope !8
+; CHECK-NEXT: [[WIDE_LOAD17:%.*]] = load <8 x i32>, ptr [[TMP12]], align 8, !alias.scope [[META8:![0-9]+]]
; CHECK-NEXT: [[TMP13]] = add <8 x i32> [[VEC_PHI16]], [[WIDE_LOAD17]]
-; CHECK-NEXT: store i32 [[NTRUNC]], ptr [[A]], align 4, !alias.scope !11, !noalias !8
+; CHECK-NEXT: store i32 [[NTRUNC]], ptr [[A]], align 4, !alias.scope [[META11:![0-9]+]], !noalias [[META8]]
; CHECK-NEXT: [[INDEX_NEXT18]] = add nuw i64 [[INDEX15]], 8
; CHECK-NEXT: [[TMP14:%.*]] = icmp eq i64 [[INDEX_NEXT18]], [[N_VEC13]]
; CHECK-NEXT: br i1 [[TMP14]], label [[VEC_EPILOG_MIDDLE_BLOCK:%.*]], label [[VEC_EPILOG_VECTOR_BODY]], !llvm.loop [[LOOP13:![0-9]+]]
@@ -127,11 +126,10 @@ define void @inv_val_store_to_inv_address_conditional(ptr %a, i64 %n, ptr %b, i3
; CHECK-NEXT: iter.check:
; CHECK-NEXT: [[NTRUNC:%.*]] = trunc i64 [[N:%.*]] to i32
; CHECK-NEXT: [[SMAX2:%.*]] = call i64 @llvm.smax.i64(i64 [[N]], i64 1)
-; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[SMAX2]], 8
+; CHECK-NEXT: [[MIN_ITERS_CHECK:%.*]] = icmp slt i64 [[N]], 8
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK]], label [[VEC_EPILOG_SCALAR_PH:%.*]], label [[VECTOR_MEMCHECK:%.*]]
; CHECK: vector.memcheck:
-; CHECK-NEXT: [[SMAX:%.*]] = call i64 @llvm.smax.i64(i64 [[N]], i64 1)
-; CHECK-NEXT: [[TMP0:%.*]] = shl i64 [[SMAX]], 2
+; CHECK-NEXT: [[TMP0:%.*]] = shl i64 [[N]], 2
; CHECK-NEXT: [[SCEVGEP:%.*]] = getelementptr i8, ptr [[B:%.*]], i64 [[TMP0]]
; CHECK-NEXT: [[SCEVGEP1:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 4
; CHECK-NEXT: [[BOUND0:%.*]] = icmp ugt ptr [[SCEVGEP1]], [[B]]
@@ -139,7 +137,7 @@ define void @inv_val_store_to_inv_address_conditional(ptr %a, i64 %n, ptr %b, i3
; CHECK-NEXT: [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
; CHECK-NEXT: br i1 [[FOUND_CONFLICT]], label [[VEC_EPILOG_SCALAR_PH]], label [[VECTOR_MAIN_LOOP_ITER_CHECK:%.*]]
; CHECK: vector.main.loop.iter.check:
-; CHECK-NEXT: [[MIN_ITERS_CHECK3:%.*]] = icmp ult i64 [[SMAX2]], 16
+; CHECK-NEXT: [[MIN_ITERS_CHECK3:%.*]] = icmp slt i64 [[N]], 16
; CHECK-NEXT: br i1 [[MIN_ITERS_CHECK3]], label [[VEC_EPILOG_PH:%.*]], label [[VECTOR_PH:%.*]]
; CHECK: vector.ph:
; CHECK-NEXT: [[N_VEC:%.*]] = and i64 [[SMAX2]], 9223372036854775792
@@ -153,10 +151,10 @@ define void @inv_val_store_to_inv_address_conditional(ptr %a, i64 %n, ptr %b, i3
; CHECK: vector.body:
; CHECK-NEXT: [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
; CHECK-NEXT: [[TMP1:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[INDEX]]
-; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <16 x i32>, ptr [[TMP1]], align 8, !alias.scope !15, !noalias !18
+; CHECK-NEXT: [[WIDE_LOAD:%.*]] = load <16 x i32>, ptr [[TMP1]], align 8, !alias.scope [[META15:![0-9]+]], !noalias [[META18:![0-9]+]]
; CHECK-NEXT: [[TMP2:%.*]] = icmp eq <16 x i32> [[WIDE_LOAD]], [[BROADCAST_SPLAT]]
-; CHECK-NEXT: store <16 x i32> [[BROADCAST_SPLAT5]], ptr [[TMP1]], align 4, !alias.scope !15, !noalias !18
-; CHECK-NEXT: call void @llvm.masked.scatter.v16i32.v16p0(<16 x i32> [[BROADCAST_SPLAT5]], <16 x ptr> [[BROADCAST_SPLAT7]], i32 4, <16 x i1> [[TMP2]]), !alias.scope !18
+; CHECK-NEXT: store <16 x i32> [[BROADCAST_SPLAT5]], ptr [[TMP1]], align 4, !alias.scope [[META15]], !noalias [[META18]]
+; CHECK-NEXT: call void @llvm.masked.scatter.v16i32.v16p0(<16 x i32> [[BROADCAST_SPLAT5]], <16 x ptr> [[BROADCAST_SPLAT7]], i32 4, <16 x i1> [[TMP2]]), !alias.scope [[META18]]
; CHECK-NEXT: [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 16
; CHECK-NEXT: [[TMP3:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
; CHECK-NEXT: br i1 [[TMP3]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP20:![0-9]+]]
@@ -180,10 +178,10 @@ define void @inv_val_store_to_inv_address_conditional(ptr %a, i64 %n, ptr %b, i3
; CHECK: vec.epilog.vector.body:
; CHECK-NEXT: [[INDEX11:%.*]] = phi i64 [ [[VEC_EPILOG_RESUME_VAL]], [[VEC_EPILOG_PH]] ], [ [[INDEX_NEXT19:%.*]]...
[truncated]
|
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@nikic Any thoughts? |
…ion when folding `icmp Pred min|max(X, Y), Z`
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Yes, we should, though I don't think it should be |
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This patch tries to flip the signedness of predicates when folding an unsigned icmp with a signed min/max. It will enable more optimizations as we canonicalizes a signed icmp into an unsigned icmp when both operands are known to have the same sign.
Fixes #76672.
Compile-time impact: http://llvm-compile-time-tracker.com/compare.php?from=949ec83eaf6fa6dbffb94c2ea9c0a4d5efdbd239&to=2deca1aea8a4e13609bab72c522a97d424f0fc2d&stat=instructions:u
NOTE: We can flip the signedness of predicate if both operands are negative. But I don't see the benefit of handling these cases.
BTW, should we add a flag like
nnegto indicate that an unsigned icmp can be treated as a signed one?