nemanjai requested changes to this revision. nemanjai added a comment. This revision now requires changes to proceed.
I may be wrong, but I really think this is incorrect. Please do some functional (execution) testing on this. Also, please re-title this from "truncate results" to something like "truncate exponent parameter" or similar since you are not truncating the result but the parameter. ================ Comment at: clang/lib/Headers/altivec.h:3178 + : (__builtin_vsx_xvcvuxdsp((vector unsigned long long)(__a)) * \ + (vector float)(vector unsigned)((0x7f - (__b)) << 23 & 0x1F)), \ + vector signed long long \ ---------------- Hmm... aren't you truncating the wrong thing here (and for all the other shifted ones? Shouldn't it be something like: ``` (vector float)(vector unsigned)((0x7f - ((__b) & 0x1F)) << 23)), ``` ================ Comment at: clang/test/CodeGen/builtins-ppc-xlcompat.c:25 // CHECK-NEXT: [[TMP1:%.*]] = call <4 x float> @llvm.ppc.vsx.xvcvsxdsp(<2 x i64> [[TMP0]]) -// CHECK-NEXT: fmul <4 x float> [[TMP1]], <float 6.250000e-02, float 6.250000e-02, float 6.250000e-02, float 6.250000e-02> +// CHECK-NEXT: fmul <4 x float> [[TMP1]], zeroinitializer ---------------- Notice that all the `fmul`'s multiply by zero. This really doesn't seem right - and is likely due to shifting left and then truncating (i.e. you shift a value left by 23/52 bits, then you bitwise-and it with 0x1F - all you're going to get are zeros). Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D106409/new/ https://reviews.llvm.org/D106409 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
