[llvm] a258894 - Fix convertBFloatAPFloatToAPInt for NaN/Inf values

[Diego Caballero via llvm-commits]

Author: Diego Caballero
Date: 2020-06-05T17:22:43-07:00
New Revision: a2588948febccfed5ba074fc32dcb093484fa5c8

URL: https://github.com/llvm/llvm-project/commit/a2588948febccfed5ba074fc32dcb093484fa5c8
DIFF: https://github.com/llvm/llvm-project/commit/a2588948febccfed5ba074fc32dcb093484fa5c8.diff

LOG: Fix convertBFloatAPFloatToAPInt for NaN/Inf values

Bfloat type has an 8-bit exponent so the exponent of NaN/Inf numbers
must be 0xff instead of 0x1f. This is probably a copy-paste mistake
from the half float type.

Reviewed By: lattner

Differential Revision: https://reviews.llvm.org/D81302

Added: 
    

Modified: 
    llvm/lib/Support/APFloat.cpp
    llvm/test/Assembler/bfloat.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Support/APFloat.cpp b/llvm/lib/Support/APFloat.cpp
index 78f44c5e47bb..569cac790af9 100644
--- a/llvm/lib/Support/APFloat.cpp
+++ b/llvm/lib/Support/APFloat.cpp
@@ -3278,11 +3278,11 @@ APInt IEEEFloat::convertBFloatAPFloatToAPInt() const {
     myexponent = 0;
     mysignificand = 0;
   } else if (category == fcInfinity) {
-    myexponent = 0x1f;
+    myexponent = 0xff;
     mysignificand = 0;
   } else {
     assert(category == fcNaN && "Unknown category!");
-    myexponent = 0x1f;
+    myexponent = 0xff;
     mysignificand = (uint32_t)*significandParts();
   }
 

diff  --git a/llvm/test/Assembler/bfloat.ll b/llvm/test/Assembler/bfloat.ll
index c9c7b6d26868..3a3b4c2b277d 100644
--- a/llvm/test/Assembler/bfloat.ll
+++ b/llvm/test/Assembler/bfloat.ll
@@ -36,3 +36,27 @@ define float @check_bfloat_convert() {
 ; OPT: 0x4191A00000000000
   ret float %tmp
 }
+
+; ASSEM-DISASS-LABEL @snan_bfloat
+define bfloat @snan_bfloat() {
+; ASSEM-DISASS: ret bfloat 0xR7F81
+    ret bfloat 0xR7F81
+}
+
+; ASSEM-DISASS-LABEL @qnan_bfloat
+define bfloat @qnan_bfloat() {
+; ASSEM-DISASS: ret bfloat 0xR7FC0
+    ret bfloat 0xR7FC0
+}
+
+; ASSEM-DISASS-LABEL @pos_inf_bfloat
+define bfloat @pos_inf_bfloat() {
+; ASSEM-DISASS: ret bfloat 0xR7F80
+    ret bfloat 0xR7F80
+}
+
+; ASSEM-DISASS-LABEL @neg_inf_bfloat
+define bfloat @neg_inf_bfloat() {
+; ASSEM-DISASS: ret bfloat 0xRFF80
+    ret bfloat 0xRFF80
+}