ac: use llvm.amdgcn.fract intrinsic for nir_op_ffract

Noticed with a Doom shader.

29077 shaders in 15096 tests
Totals:
SGPRS: 1282125 -> 1282133 (0.00 %)
VGPRS: 908716 -> 908616 (-0.01 %)
Spilled SGPRs: 24811 -> 24779 (-0.13 %)
Code Size: 49048176 -> 48936488 (-0.23 %) bytes
Max Waves: 244232 -> 244226 (-0.00 %)

Totals from affected shaders:
SGPRS: 229584 -> 229592 (0.00 %)
VGPRS: 163268 -> 163168 (-0.06 %)
Spilled SGPRs: 8682 -> 8650 (-0.37 %)
Code Size: 12819572 -> 12707884 (-0.87 %) bytes
Max Waves: 24398 -> 24392 (-0.02 %)

Signed-off-by: Samuel Pitoiset <samuel.pitoiset@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>

diff --git a/src/amd/common/ac_llvm_build.c b/src/amd/common/ac_llvm_build.c
index 0cab4d4a9b59d57cc10e1ef4a97fb36ed0323669..9cf1c6f8792e81fb690d6b716d539c452358ae96 100644 (file)
--- a/src/amd/common/ac_llvm_build.c
+++ b/src/amd/common/ac_llvm_build.c
@@ -2155,19 +2155,18 @@ LLVMValueRef ac_build_fract(struct ac_llvm_context *ctx, LLVMValueRef src0,
        char *intr;
 
        if (bitsize == 32) {
-               intr = "llvm.floor.f32";
+               intr = "llvm.amdgcn.fract.f32";
                type = ctx->f32;
        } else {
-               intr = "llvm.floor.f64";
+               intr = "llvm.amdgcn.fract.f64";
                type = ctx->f64;
        }
 
        LLVMValueRef params[] = {
                src0,
        };
-       LLVMValueRef floor = ac_build_intrinsic(ctx, intr, type, params, 1,
-                                               AC_FUNC_ATTR_READNONE);
-       return LLVMBuildFSub(ctx->builder, src0, floor, "");
+       return ac_build_intrinsic(ctx, intr, type, params, 1,
+                                 AC_FUNC_ATTR_READNONE);
 }
 
 LLVMValueRef ac_build_isign(struct ac_llvm_context *ctx, LLVMValueRef src0,