[WebAssembly] Don't assume that zext/sext result is i32/i64 in fast isel (PR41841)

Usually this will abort fast-isel at the instruction using the
non-legal result, but if the only use is in a different basic block,
we'll incorrectly assume that the zext/sext is to i32 (rather than
i128 in this case).

Differential Revision: https://reviews.llvm.org/D61823

llvm-svn: 360616

1 files changed, 8 insertions, 2 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp b/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
index 535a925..39c682d 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyFastISel.cpp
@@ -523,7 +523,10 @@ unsigned WebAssemblyFastISel::zeroExtend(unsigned Reg, const Value *V,
     return Result;
   }
 
-  return zeroExtendToI32(Reg, V, From);
+  if (To == MVT::i32)
+    return zeroExtendToI32(Reg, V, From);
+
+  return 0;
 }
 
 unsigned WebAssemblyFastISel::signExtend(unsigned Reg, const Value *V,
@@ -542,7 +545,10 @@ unsigned WebAssemblyFastISel::signExtend(unsigned Reg, const Value *V,
     return Result;
   }
 
-  return signExtendToI32(Reg, V, From);
+  if (To == MVT::i32)
+    return signExtendToI32(Reg, V, From);
+
+  return 0;
 }
 
 unsigned WebAssemblyFastISel::getRegForUnsignedValue(const Value *V) {