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Diffstat (limited to 'llvm/test/Transforms/SROA/phi-and-select.ll')
| -rw-r--r-- | llvm/test/Transforms/SROA/phi-and-select.ll | 646 |
1 files changed, 646 insertions, 0 deletions
diff --git a/llvm/test/Transforms/SROA/phi-and-select.ll b/llvm/test/Transforms/SROA/phi-and-select.ll new file mode 100644 index 00000000000..d0904cecd9f --- /dev/null +++ b/llvm/test/Transforms/SROA/phi-and-select.ll @@ -0,0 +1,646 @@ +; RUN: opt < %s -sroa -S | FileCheck %s +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-n8:16:32:64" + +define i32 @test1() { +; CHECK-LABEL: @test1( +entry: + %a = alloca [2 x i32] +; CHECK-NOT: alloca + + %a0 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 0 + %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1 + store i32 0, i32* %a0 + store i32 1, i32* %a1 + %v0 = load i32, i32* %a0 + %v1 = load i32, i32* %a1 +; CHECK-NOT: store +; CHECK-NOT: load + + %cond = icmp sle i32 %v0, %v1 + br i1 %cond, label %then, label %exit + +then: + br label %exit + +exit: + %phi = phi i32* [ %a1, %then ], [ %a0, %entry ] +; CHECK: phi i32 [ 1, %{{.*}} ], [ 0, %{{.*}} ] + + %result = load i32, i32* %phi + ret i32 %result +} + +define i32 @test2() { +; CHECK-LABEL: @test2( +entry: + %a = alloca [2 x i32] +; CHECK-NOT: alloca + + %a0 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 0 + %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1 + store i32 0, i32* %a0 + store i32 1, i32* %a1 + %v0 = load i32, i32* %a0 + %v1 = load i32, i32* %a1 +; CHECK-NOT: store +; CHECK-NOT: load + + %cond = icmp sle i32 %v0, %v1 + %select = select i1 %cond, i32* %a1, i32* %a0 +; CHECK: select i1 %{{.*}}, i32 1, i32 0 + + %result = load i32, i32* %select + ret i32 %result +} + +define i32 @test3(i32 %x) { +; CHECK-LABEL: @test3( +entry: + %a = alloca [2 x i32] +; CHECK-NOT: alloca + + ; Note that we build redundant GEPs here to ensure that having different GEPs + ; into the same alloca partation continues to work with PHI speculation. This + ; was the underlying cause of PR13926. + %a0 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 0 + %a0b = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 0 + %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1 + %a1b = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1 + store i32 0, i32* %a0 + store i32 1, i32* %a1 +; CHECK-NOT: store + + switch i32 %x, label %bb0 [ i32 1, label %bb1 + i32 2, label %bb2 + i32 3, label %bb3 + i32 4, label %bb4 + i32 5, label %bb5 + i32 6, label %bb6 + i32 7, label %bb7 ] + +bb0: + br label %exit +bb1: + br label %exit +bb2: + br label %exit +bb3: + br label %exit +bb4: + br label %exit +bb5: + br label %exit +bb6: + br label %exit +bb7: + br label %exit + +exit: + %phi = phi i32* [ %a1, %bb0 ], [ %a0, %bb1 ], [ %a0, %bb2 ], [ %a1, %bb3 ], + [ %a1b, %bb4 ], [ %a0b, %bb5 ], [ %a0b, %bb6 ], [ %a1b, %bb7 ] +; CHECK: phi i32 [ 1, %{{.*}} ], [ 0, %{{.*}} ], [ 0, %{{.*}} ], [ 1, %{{.*}} ], [ 1, %{{.*}} ], [ 0, %{{.*}} ], [ 0, %{{.*}} ], [ 1, %{{.*}} ] + + %result = load i32, i32* %phi + ret i32 %result +} + +define i32 @test4() { +; CHECK-LABEL: @test4( +entry: + %a = alloca [2 x i32] +; CHECK-NOT: alloca + + %a0 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 0 + %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1 + store i32 0, i32* %a0 + store i32 1, i32* %a1 + %v0 = load i32, i32* %a0 + %v1 = load i32, i32* %a1 +; CHECK-NOT: store +; CHECK-NOT: load + + %cond = icmp sle i32 %v0, %v1 + %select = select i1 %cond, i32* %a0, i32* %a0 +; CHECK-NOT: select + + %result = load i32, i32* %select + ret i32 %result +; CHECK: ret i32 0 +} + +define i32 @test5(i32* %b) { +; CHECK-LABEL: @test5( +entry: + %a = alloca [2 x i32] +; CHECK-NOT: alloca + + %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1 + store i32 1, i32* %a1 +; CHECK-NOT: store + + %select = select i1 true, i32* %a1, i32* %b +; CHECK-NOT: select + + %result = load i32, i32* %select +; CHECK-NOT: load + + ret i32 %result +; CHECK: ret i32 1 +} + +declare void @f(i32*, i32*) + +define i32 @test6(i32* %b) { +; CHECK-LABEL: @test6( +entry: + %a = alloca [2 x i32] + %c = alloca i32 +; CHECK-NOT: alloca + + %a1 = getelementptr [2 x i32], [2 x i32]* %a, i64 0, i32 1 + store i32 1, i32* %a1 + + %select = select i1 true, i32* %a1, i32* %b + %select2 = select i1 false, i32* %a1, i32* %b + %select3 = select i1 false, i32* %c, i32* %b +; CHECK: %[[select2:.*]] = select i1 false, i32* undef, i32* %b +; CHECK: %[[select3:.*]] = select i1 false, i32* undef, i32* %b + + ; Note, this would potentially escape the alloca pointer except for the + ; constant folding of the select. + call void @f(i32* %select2, i32* %select3) +; CHECK: call void @f(i32* %[[select2]], i32* %[[select3]]) + + + %result = load i32, i32* %select +; CHECK-NOT: load + + %dead = load i32, i32* %c + + ret i32 %result +; CHECK: ret i32 1 +} + +define i32 @test7() { +; CHECK-LABEL: @test7( +; CHECK-NOT: alloca + +entry: + %X = alloca i32 + br i1 undef, label %good, label %bad + +good: + %Y1 = getelementptr i32, i32* %X, i64 0 + store i32 0, i32* %Y1 + br label %exit + +bad: + %Y2 = getelementptr i32, i32* %X, i64 1 + store i32 0, i32* %Y2 + br label %exit + +exit: + %P = phi i32* [ %Y1, %good ], [ %Y2, %bad ] +; CHECK: %[[phi:.*]] = phi i32 [ 0, %good ], + %Z2 = load i32, i32* %P + ret i32 %Z2 +; CHECK: ret i32 %[[phi]] +} + +define i32 @test8(i32 %b, i32* %ptr) { +; Ensure that we rewrite allocas to the used type when that use is hidden by +; a PHI that can be speculated. +; CHECK-LABEL: @test8( +; CHECK-NOT: alloca +; CHECK-NOT: load +; CHECK: %[[value:.*]] = load i32, i32* %ptr +; CHECK-NOT: load +; CHECK: %[[result:.*]] = phi i32 [ undef, %else ], [ %[[value]], %then ] +; CHECK-NEXT: ret i32 %[[result]] + +entry: + %f = alloca float + %test = icmp ne i32 %b, 0 + br i1 %test, label %then, label %else + +then: + br label %exit + +else: + %bitcast = bitcast float* %f to i32* + br label %exit + +exit: + %phi = phi i32* [ %bitcast, %else ], [ %ptr, %then ] + %loaded = load i32, i32* %phi, align 4 + ret i32 %loaded +} + +define i32 @test9(i32 %b, i32* %ptr) { +; Same as @test8 but for a select rather than a PHI node. +; CHECK-LABEL: @test9( +; CHECK-NOT: alloca +; CHECK-NOT: load +; CHECK: %[[value:.*]] = load i32, i32* %ptr +; CHECK-NOT: load +; CHECK: %[[result:.*]] = select i1 %{{.*}}, i32 undef, i32 %[[value]] +; CHECK-NEXT: ret i32 %[[result]] + +entry: + %f = alloca float + store i32 0, i32* %ptr + %test = icmp ne i32 %b, 0 + %bitcast = bitcast float* %f to i32* + %select = select i1 %test, i32* %bitcast, i32* %ptr + %loaded = load i32, i32* %select, align 4 + ret i32 %loaded +} + +define float @test10(i32 %b, float* %ptr) { +; Don't try to promote allocas which are not elligible for it even after +; rewriting due to the necessity of inserting bitcasts when speculating a PHI +; node. +; CHECK-LABEL: @test10( +; CHECK: %[[alloca:.*]] = alloca +; CHECK: %[[argvalue:.*]] = load float, float* %ptr +; CHECK: %[[cast:.*]] = bitcast double* %[[alloca]] to float* +; CHECK: %[[allocavalue:.*]] = load float, float* %[[cast]] +; CHECK: %[[result:.*]] = phi float [ %[[allocavalue]], %else ], [ %[[argvalue]], %then ] +; CHECK-NEXT: ret float %[[result]] + +entry: + %f = alloca double + store double 0.0, double* %f + %test = icmp ne i32 %b, 0 + br i1 %test, label %then, label %else + +then: + br label %exit + +else: + %bitcast = bitcast double* %f to float* + br label %exit + +exit: + %phi = phi float* [ %bitcast, %else ], [ %ptr, %then ] + %loaded = load float, float* %phi, align 4 + ret float %loaded +} + +define float @test11(i32 %b, float* %ptr) { +; Same as @test10 but for a select rather than a PHI node. +; CHECK-LABEL: @test11( +; CHECK: %[[alloca:.*]] = alloca +; CHECK: %[[cast:.*]] = bitcast double* %[[alloca]] to float* +; CHECK: %[[allocavalue:.*]] = load float, float* %[[cast]] +; CHECK: %[[argvalue:.*]] = load float, float* %ptr +; CHECK: %[[result:.*]] = select i1 %{{.*}}, float %[[allocavalue]], float %[[argvalue]] +; CHECK-NEXT: ret float %[[result]] + +entry: + %f = alloca double + store double 0.0, double* %f + store float 0.0, float* %ptr + %test = icmp ne i32 %b, 0 + %bitcast = bitcast double* %f to float* + %select = select i1 %test, float* %bitcast, float* %ptr + %loaded = load float, float* %select, align 4 + ret float %loaded +} + +define i32 @test12(i32 %x, i32* %p) { +; Ensure we don't crash or fail to nuke dead selects of allocas if no load is +; never found. +; CHECK-LABEL: @test12( +; CHECK-NOT: alloca +; CHECK-NOT: select +; CHECK: ret i32 %x + +entry: + %a = alloca i32 + store i32 %x, i32* %a + %dead = select i1 undef, i32* %a, i32* %p + %load = load i32, i32* %a + ret i32 %load +} + +define i32 @test13(i32 %x, i32* %p) { +; Ensure we don't crash or fail to nuke dead phis of allocas if no load is ever +; found. +; CHECK-LABEL: @test13( +; CHECK-NOT: alloca +; CHECK-NOT: phi +; CHECK: ret i32 %x + +entry: + %a = alloca i32 + store i32 %x, i32* %a + br label %loop + +loop: + %phi = phi i32* [ %p, %entry ], [ %a, %loop ] + br i1 undef, label %loop, label %exit + +exit: + %load = load i32, i32* %a + ret i32 %load +} + +define i32 @test14(i1 %b1, i1 %b2, i32* %ptr) { +; Check for problems when there are both selects and phis and one is +; speculatable toward promotion but the other is not. That should block all of +; the speculation. +; CHECK-LABEL: @test14( +; CHECK: alloca +; CHECK: alloca +; CHECK: select +; CHECK: phi +; CHECK: phi +; CHECK: select +; CHECK: ret i32 + +entry: + %f = alloca i32 + %g = alloca i32 + store i32 0, i32* %f + store i32 0, i32* %g + %f.select = select i1 %b1, i32* %f, i32* %ptr + br i1 %b2, label %then, label %else + +then: + br label %exit + +else: + br label %exit + +exit: + %f.phi = phi i32* [ %f, %then ], [ %f.select, %else ] + %g.phi = phi i32* [ %g, %then ], [ %ptr, %else ] + %f.loaded = load i32, i32* %f.phi + %g.select = select i1 %b1, i32* %g, i32* %g.phi + %g.loaded = load i32, i32* %g.select + %result = add i32 %f.loaded, %g.loaded + ret i32 %result +} + +define i32 @PR13905() { +; Check a pattern where we have a chain of dead phi nodes to ensure they are +; deleted and promotion can proceed. +; CHECK-LABEL: @PR13905( +; CHECK-NOT: alloca i32 +; CHECK: ret i32 undef + +entry: + %h = alloca i32 + store i32 0, i32* %h + br i1 undef, label %loop1, label %exit + +loop1: + %phi1 = phi i32* [ null, %entry ], [ %h, %loop1 ], [ %h, %loop2 ] + br i1 undef, label %loop1, label %loop2 + +loop2: + br i1 undef, label %loop1, label %exit + +exit: + %phi2 = phi i32* [ %phi1, %loop2 ], [ null, %entry ] + ret i32 undef +} + +define i32 @PR13906() { +; Another pattern which can lead to crashes due to failing to clear out dead +; PHI nodes or select nodes. This triggers subtly differently from the above +; cases because the PHI node is (recursively) alive, but the select is dead. +; CHECK-LABEL: @PR13906( +; CHECK-NOT: alloca + +entry: + %c = alloca i32 + store i32 0, i32* %c + br label %for.cond + +for.cond: + %d.0 = phi i32* [ undef, %entry ], [ %c, %if.then ], [ %d.0, %for.cond ] + br i1 undef, label %if.then, label %for.cond + +if.then: + %tmpcast.d.0 = select i1 undef, i32* %c, i32* %d.0 + br label %for.cond +} + +define i64 @PR14132(i1 %flag) { +; CHECK-LABEL: @PR14132( +; Here we form a PHI-node by promoting the pointer alloca first, and then in +; order to promote the other two allocas, we speculate the load of the +; now-phi-node-pointer. In doing so we end up loading a 64-bit value from an i8 +; alloca. While this is a bit dubious, we were asserting on trying to +; rewrite it. The trick is that the code using the value may carefully take +; steps to only use the not-undef bits, and so we need to at least loosely +; support this.. +entry: + %a = alloca i64, align 8 + %b = alloca i8, align 8 + %ptr = alloca i64*, align 8 +; CHECK-NOT: alloca + + %ptr.cast = bitcast i64** %ptr to i8** + store i64 0, i64* %a, align 8 + store i8 1, i8* %b, align 8 + store i64* %a, i64** %ptr, align 8 + br i1 %flag, label %if.then, label %if.end + +if.then: + store i8* %b, i8** %ptr.cast, align 8 + br label %if.end +; CHECK-NOT: store +; CHECK: %[[ext:.*]] = zext i8 1 to i64 + +if.end: + %tmp = load i64*, i64** %ptr, align 8 + %result = load i64, i64* %tmp, align 8 +; CHECK-NOT: load +; CHECK: %[[result:.*]] = phi i64 [ %[[ext]], %if.then ], [ 0, %entry ] + + ret i64 %result +; CHECK-NEXT: ret i64 %[[result]] +} + +define float @PR16687(i64 %x, i1 %flag) { +; CHECK-LABEL: @PR16687( +; Check that even when we try to speculate the same phi twice (in two slices) +; on an otherwise promotable construct, we don't get ahead of ourselves and try +; to promote one of the slices prior to speculating it. + +entry: + %a = alloca i64, align 8 + store i64 %x, i64* %a + br i1 %flag, label %then, label %else +; CHECK-NOT: alloca +; CHECK-NOT: store +; CHECK: %[[lo:.*]] = trunc i64 %x to i32 +; CHECK: %[[shift:.*]] = lshr i64 %x, 32 +; CHECK: %[[hi:.*]] = trunc i64 %[[shift]] to i32 + +then: + %a.f = bitcast i64* %a to float* + br label %end +; CHECK: %[[lo_cast:.*]] = bitcast i32 %[[lo]] to float + +else: + %a.raw = bitcast i64* %a to i8* + %a.raw.4 = getelementptr i8, i8* %a.raw, i64 4 + %a.raw.4.f = bitcast i8* %a.raw.4 to float* + br label %end +; CHECK: %[[hi_cast:.*]] = bitcast i32 %[[hi]] to float + +end: + %a.phi.f = phi float* [ %a.f, %then ], [ %a.raw.4.f, %else ] + %f = load float, float* %a.phi.f + ret float %f +; CHECK: %[[phi:.*]] = phi float [ %[[lo_cast]], %then ], [ %[[hi_cast]], %else ] +; CHECK-NOT: load +; CHECK: ret float %[[phi]] +} + +; Verifies we fixed PR20425. We should be able to promote all alloca's to +; registers in this test. +; +; %0 = slice +; %1 = slice +; %2 = phi(%0, %1) // == slice +define float @simplify_phi_nodes_that_equal_slice(i1 %cond, float* %temp) { +; CHECK-LABEL: @simplify_phi_nodes_that_equal_slice( +entry: + %arr = alloca [4 x float], align 4 +; CHECK-NOT: alloca + br i1 %cond, label %then, label %else + +then: + %0 = getelementptr inbounds [4 x float], [4 x float]* %arr, i64 0, i64 3 + store float 1.000000e+00, float* %0, align 4 + br label %merge + +else: + %1 = getelementptr inbounds [4 x float], [4 x float]* %arr, i64 0, i64 3 + store float 2.000000e+00, float* %1, align 4 + br label %merge + +merge: + %2 = phi float* [ %0, %then ], [ %1, %else ] + store float 0.000000e+00, float* %temp, align 4 + %3 = load float, float* %2, align 4 + ret float %3 +} + +; A slightly complicated example for PR20425. +; +; %0 = slice +; %1 = phi(%0) // == slice +; %2 = slice +; %3 = phi(%1, %2) // == slice +define float @simplify_phi_nodes_that_equal_slice_2(i1 %cond, float* %temp) { +; CHECK-LABEL: @simplify_phi_nodes_that_equal_slice_2( +entry: + %arr = alloca [4 x float], align 4 +; CHECK-NOT: alloca + br i1 %cond, label %then, label %else + +then: + %0 = getelementptr inbounds [4 x float], [4 x float]* %arr, i64 0, i64 3 + store float 1.000000e+00, float* %0, align 4 + br label %then2 + +then2: + %1 = phi float* [ %0, %then ] + store float 2.000000e+00, float* %1, align 4 + br label %merge + +else: + %2 = getelementptr inbounds [4 x float], [4 x float]* %arr, i64 0, i64 3 + store float 3.000000e+00, float* %2, align 4 + br label %merge + +merge: + %3 = phi float* [ %1, %then2 ], [ %2, %else ] + store float 0.000000e+00, float* %temp, align 4 + %4 = load float, float* %3, align 4 + ret float %4 +} + +%struct.S = type { i32 } + +; Verifies we fixed PR20822. We have a foldable PHI feeding a speculatable PHI +; which requires the rewriting of the speculated PHI to handle insertion +; when the incoming pointer is itself from a PHI node. We would previously +; insert a bitcast instruction *before* a PHI, producing an invalid module; +; make sure we insert *after* the first non-PHI instruction. +define void @PR20822() { +; CHECK-LABEL: @PR20822( +entry: + %f = alloca %struct.S, align 4 +; CHECK: %[[alloca:.*]] = alloca + br i1 undef, label %if.end, label %for.cond + +for.cond: ; preds = %for.cond, %entry + br label %if.end + +if.end: ; preds = %for.cond, %entry + %f2 = phi %struct.S* [ %f, %entry ], [ %f, %for.cond ] +; CHECK: phi i32 +; CHECK: %[[cast:.*]] = bitcast i32* %[[alloca]] to %struct.S* + phi i32 [ undef, %entry ], [ undef, %for.cond ] + br i1 undef, label %if.then5, label %if.then2 + +if.then2: ; preds = %if.end + br label %if.then5 + +if.then5: ; preds = %if.then2, %if.end + %f1 = phi %struct.S* [ undef, %if.then2 ], [ %f2, %if.end ] +; CHECK: phi {{.*}} %[[cast]] + store %struct.S undef, %struct.S* %f1, align 4 + ret void +} + +define i32 @phi_align(i32* %z) { +; CHECK-LABEL: @phi_align( +entry: + %a = alloca [8 x i8], align 8 +; CHECK: alloca [7 x i8] + + %a0x = getelementptr [8 x i8], [8 x i8]* %a, i64 0, i32 1 + %a0 = bitcast i8* %a0x to i32* + %a1x = getelementptr [8 x i8], [8 x i8]* %a, i64 0, i32 4 + %a1 = bitcast i8* %a1x to i32* +; CHECK: store i32 0, {{.*}}, align 1 + store i32 0, i32* %a0, align 1 +; CHECK: store i32 1, {{.*}}, align 1 + store i32 1, i32* %a1, align 4 +; CHECK: load {{.*}}, align 1 + %v0 = load i32, i32* %a0, align 1 +; CHECK: load {{.*}}, align 1 + %v1 = load i32, i32* %a1, align 4 + %cond = icmp sle i32 %v0, %v1 + br i1 %cond, label %then, label %exit + +then: + br label %exit + +exit: +; CHECK: %phi = phi i32* [ {{.*}}, %then ], [ %z, %entry ] +; CHECK-NEXT: %result = load i32, i32* %phi, align 1 + %phi = phi i32* [ %a1, %then ], [ %z, %entry ] + %result = load i32, i32* %phi, align 4 + ret i32 %result +} + +; Don't speculate a load based on an earlier volatile operation. +define i8 @volatile_select(i8* %p, i1 %b) { +; CHECK-LABEL: @volatile_select( +; CHECK: select i1 %b, i8* %p, i8* %p2 + %p2 = alloca i8 + store i8 0, i8* %p2 + store volatile i8 0, i8* %p + %px = select i1 %b, i8* %p, i8* %p2 + %v2 = load i8, i8* %px + ret i8 %v2 +} |
