[llvm] c8ffc73 - [PartiallyInlineLibCalls] Don't crash when there's a writeonly attribute on the call

[Benjamin Kramer via llvm-commits]

Author: Benjamin Kramer
Date: 2022-01-05T12:16:26+01:00
New Revision: c8ffc73350dbb6044ca947bbead127b9b914cdf3

URL: https://github.com/llvm/llvm-project/commit/c8ffc73350dbb6044ca947bbead127b9b914cdf3
DIFF: https://github.com/llvm/llvm-project/commit/c8ffc73350dbb6044ca947bbead127b9b914cdf3.diff

LOG: [PartiallyInlineLibCalls] Don't crash when there's a writeonly attribute on the call

readnone subsumes writeonly, so just swap out the attributes. The
verifier doesn't allow us to have both on a call.

Added: 
    

Modified: 
    llvm/lib/Transforms/Scalar/PartiallyInlineLibCalls.cpp
    llvm/test/Transforms/PartiallyInlineLibCalls/X86/good-prototype.ll

Removed: 
    


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diff  --git a/llvm/lib/Transforms/Scalar/PartiallyInlineLibCalls.cpp b/llvm/lib/Transforms/Scalar/PartiallyInlineLibCalls.cpp
index 44027ccd92ca2..e0d0301c1ef62 100644
--- a/llvm/lib/Transforms/Scalar/PartiallyInlineLibCalls.cpp
+++ b/llvm/lib/Transforms/Scalar/PartiallyInlineLibCalls.cpp
@@ -82,6 +82,7 @@ static bool optimizeSQRT(CallInst *Call, Function *CalledFunc,
 
   // Add attribute "readnone" so that backend can use a native sqrt instruction
   // for this call.
+  Call->removeFnAttr(Attribute::WriteOnly);
   Call->addFnAttr(Attribute::ReadNone);
 
   // Insert a FP compare instruction and use it as the CurrBB branch condition.

diff  --git a/llvm/test/Transforms/PartiallyInlineLibCalls/X86/good-prototype.ll b/llvm/test/Transforms/PartiallyInlineLibCalls/X86/good-prototype.ll
index 98aa46219860b..964ce83a36a56 100644
--- a/llvm/test/Transforms/PartiallyInlineLibCalls/X86/good-prototype.ll
+++ b/llvm/test/Transforms/PartiallyInlineLibCalls/X86/good-prototype.ll
@@ -5,7 +5,7 @@
 define float @f(float %val) {
 ; CHECK-LABEL: @f(
 ; CHECK-NEXT:  entry:
-; CHECK-NEXT:    [[RES:%.*]] = tail call float @sqrtf(float [[VAL:%.*]]) #0
+; CHECK-NEXT:    [[RES:%.*]] = tail call float @sqrtf(float [[VAL:%.*]]) #[[READNONE:.*]]
 ; CHECK-NEXT:    [[TMP0:%.*]] = fcmp oge float [[VAL]], 0.000000e+00
 ; CHECK-NEXT:    br i1 [[TMP0]], label [[ENTRY_SPLIT:%.*]], label [[CALL_SQRT:%.*]]
 ; CHECK:       call.sqrt:
@@ -20,4 +20,16 @@ entry:
   ret float %res
 }
 
+define float @f_writeonly(float %val) {
+; CHECK-LABEL: @f_writeonly(
+; CHECK-NEXt:    [[RES:%.*]] = tail call float @sqrtf(float [[VAL:%.*]]) #[[READNONE]]
+  %res = tail call float @sqrtf(float %val) writeonly
+  ret float %res
+}
+
+define float @f_readonly(float %val) {
+  %res = tail call float @sqrtf(float %val) readonly
+  ret float %res
+}
+
 declare float @sqrtf(float)