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| author | dim <dim@FreeBSD.org> | 2012-04-14 13:54:10 +0000 |
|---|---|---|
| committer | dim <dim@FreeBSD.org> | 2012-04-14 13:54:10 +0000 |
| commit | 1fc08f5e9ef733ef1ce6f363fecedc2260e78974 (patch) | |
| tree | 19c69a04768629f2d440944b71cbe90adae0b615 /test/CodeGen/ARM/2012-03-26-FoldImmBug.ll | |
| parent | 07637c87f826cdf411f0673595e9bc92ebd793f2 (diff) | |
| download | FreeBSD-src-1fc08f5e9ef733ef1ce6f363fecedc2260e78974.zip FreeBSD-src-1fc08f5e9ef733ef1ce6f363fecedc2260e78974.tar.gz | |
Vendor import of llvm trunk r154661:
http://llvm.org/svn/llvm-project/llvm/trunk@r154661
Diffstat (limited to 'test/CodeGen/ARM/2012-03-26-FoldImmBug.ll')
| -rw-r--r-- | test/CodeGen/ARM/2012-03-26-FoldImmBug.ll | 33 |
1 files changed, 33 insertions, 0 deletions
diff --git a/test/CodeGen/ARM/2012-03-26-FoldImmBug.ll b/test/CodeGen/ARM/2012-03-26-FoldImmBug.ll new file mode 100644 index 0000000..0ff4f51 --- /dev/null +++ b/test/CodeGen/ARM/2012-03-26-FoldImmBug.ll @@ -0,0 +1,33 @@ +; RUN: llc < %s -mtriple=thumbv7-apple-ios -mcpu=cortex-a8 | FileCheck %s + +; ARM has a peephole optimization which looks for a def / use pair. The def +; produces a 32-bit immediate which is consumed by the use. It tries to +; fold the immediate by breaking it into two parts and fold them into the +; immmediate fields of two uses. e.g +; movw r2, #40885 +; movt r3, #46540 +; add r0, r0, r3 +; => +; add.w r0, r0, #3019898880 +; add.w r0, r0, #30146560 +; +; However, this transformation is incorrect if the user produces a flag. e.g. +; movw r2, #40885 +; movt r3, #46540 +; adds r0, r0, r3 +; => +; add.w r0, r0, #3019898880 +; adds.w r0, r0, #30146560 +; Note the adds.w may not set the carry flag even if the original sequence +; would. +; +; rdar://11116189 +define i64 @t(i64 %aInput) nounwind { +; CHECK: t: +; CHECK: movs [[REG:(r[0-9]+)]], #0 +; CHECK: movt [[REG]], #46540 +; CHECK: adds r{{[0-9]+}}, r{{[0-9]+}}, [[REG]] + %1 = mul i64 %aInput, 1000000 + %2 = add i64 %1, -7952618389194932224 + ret i64 %2 +} |
