| ; 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 |
| } |