diff options
Diffstat (limited to 'contrib/llvm/patches/patch-r271597-clang-r217410-i386-garbage-float.diff')
| -rw-r--r-- | contrib/llvm/patches/patch-r271597-clang-r217410-i386-garbage-float.diff | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/contrib/llvm/patches/patch-r271597-clang-r217410-i386-garbage-float.diff b/contrib/llvm/patches/patch-r271597-clang-r217410-i386-garbage-float.diff new file mode 100644 index 0000000..c16279a --- /dev/null +++ b/contrib/llvm/patches/patch-r271597-clang-r217410-i386-garbage-float.diff @@ -0,0 +1,64 @@ +Pull in r217410 from upstream llvm trunk (by Bob Wilson): + + Set trunc store action to Expand for all X86 targets. + + When compiling without SSE2, isTruncStoreLegal(F64, F32) would return + Legal, whereas with SSE2 it would return Expand. And since the Target + doesn't seem to actually handle a truncstore for double -> float, it + would just output a store of a full double in the space for a float + hence overwriting other bits on the stack. + + Patch by Luqman Aden! + +This should fix clang -O0 on i386 assigning garbage to floats, in +certain scenarios. + +Introduced here: http://svnweb.freebsd.org/changeset/base/271597 + +Index: lib/Target/X86/X86ISelLowering.cpp +=================================================================== +--- lib/Target/X86/X86ISelLowering.cpp (revision 208032) ++++ lib/Target/X86/X86ISelLowering.cpp (working copy) +@@ -300,6 +300,8 @@ void X86TargetLowering::resetOperationActions() { + setTruncStoreAction(MVT::i32, MVT::i8 , Expand); + setTruncStoreAction(MVT::i16, MVT::i8, Expand); + ++ setTruncStoreAction(MVT::f64, MVT::f32, Expand); ++ + // SETOEQ and SETUNE require checking two conditions. + setCondCodeAction(ISD::SETOEQ, MVT::f32, Expand); + setCondCodeAction(ISD::SETOEQ, MVT::f64, Expand); +@@ -1011,8 +1013,6 @@ void X86TargetLowering::resetOperationActions() { + AddPromotedToType (ISD::SELECT, VT, MVT::v2i64); + } + +- setTruncStoreAction(MVT::f64, MVT::f32, Expand); +- + // Custom lower v2i64 and v2f64 selects. + setOperationAction(ISD::LOAD, MVT::v2f64, Legal); + setOperationAction(ISD::LOAD, MVT::v2i64, Legal); +Index: test/CodeGen/X86/dont-trunc-store-double-to-float.ll +=================================================================== +--- test/CodeGen/X86/dont-trunc-store-double-to-float.ll (revision 0) ++++ test/CodeGen/X86/dont-trunc-store-double-to-float.ll (working copy) +@@ -0,0 +1,20 @@ ++; RUN: llc -march=x86 < %s | FileCheck %s ++ ++; CHECK-LABEL: @bar ++; CHECK: movl $1074339512, ++; CHECK: movl $1374389535, ++; CHECK: movl $1078523331, ++define void @bar() unnamed_addr { ++entry-block: ++ %a = alloca double ++ %b = alloca float ++ ++ store double 3.140000e+00, double* %a ++ %0 = load double* %a ++ ++ %1 = fptrunc double %0 to float ++ ++ store float %1, float* %b ++ ++ ret void ++} |
