8354473: Incorrect results for compress/expand tests with -XX:+EnableX86ECoreOpts

Volodymyr Paprotski · Sandhya Viswanathan · commit a6995a3d4295 · 2025-05-06T16:26:21.000Z
Reviewed-by: jbhateja, sviswanathan, epeter
diff --git a/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp b/src/hotspot/cpu/x86/c2_MacroAssembler_x86.cpp
@@ -5731,7 +5731,7 @@ void C2_MacroAssembler::vector_compress_expand_avx2(int opcode, XMMRegister dst,
   // in a permute table row contains either a valid permute index or a -1 (default)
   // value, this can potentially be used as a blending mask after
   // compressing/expanding the source vector lanes.
-  vblendvps(dst, dst, xtmp, permv, vec_enc, false, permv);
+  vblendvps(dst, dst, xtmp, permv, vec_enc, true, permv);
 }
 
 void C2_MacroAssembler::vector_compress_expand(int opcode, XMMRegister dst, XMMRegister src, KRegister mask,

Original file line number	Diff line number	Diff line change
`@@ -5731,7 +5731,7 @@ void C2_MacroAssembler::vector_compress_expand_avx2(int opcode, XMMRegister dst,`
`5731`	`5731`	`// in a permute table row contains either a valid permute index or a -1 (default)`
`5732`	`5732`	`// value, this can potentially be used as a blending mask after`
`5733`	`5733`	`// compressing/expanding the source vector lanes.`
`5734`		`- vblendvps(dst, dst, xtmp, permv, vec_enc, false, permv);`
	`5734`	`+ vblendvps(dst, dst, xtmp, permv, vec_enc, true, permv);`
`5735`	`5735`	`}`
`5736`	`5736`
`5737`	`5737`	`void C2_MacroAssembler::vector_compress_expand(int opcode, XMMRegister dst, XMMRegister src, KRegister mask,`