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authorDave Airlie <airlied@redhat.com>2017-02-16 03:42:56 +0000
committerDave Airlie <airlied@redhat.com>2017-02-16 22:57:15 +0000
commitcae1ff1a4b1f696fc6c2496d281c2548a097e753 (patch)
tree1caddae6ee3494c53476f20f9930f29d23a6e252 /src/amd
parent40bf7ba023a3a9b2027aa0b51adb6a591e472d59 (diff)
radeon/ac: add ac_emit_imsb helper.
We want to use a different intrinsic on newer llvm, so move this code to a shared area. Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net> Reviewed-by: Marek Olšák <marek.olsak@amd.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'src/amd')
-rw-r--r--src/amd/common/ac_llvm_build.c24
-rw-r--r--src/amd/common/ac_llvm_build.h4
2 files changed, 28 insertions, 0 deletions
diff --git a/src/amd/common/ac_llvm_build.c b/src/amd/common/ac_llvm_build.c
index 20216a74947..180fd2414a5 100644
--- a/src/amd/common/ac_llvm_build.c
+++ b/src/amd/common/ac_llvm_build.c
@@ -763,3 +763,27 @@ ac_emit_sendmsg(struct ac_llvm_context *ctx,
ac_emit_llvm_intrinsic(ctx, intr_name, ctx->voidt,
args, 2, 0);
}
+
+LLVMValueRef
+ac_emit_imsb(struct ac_llvm_context *ctx,
+ LLVMValueRef arg,
+ LLVMTypeRef dst_type)
+{
+ LLVMValueRef msb = ac_emit_llvm_intrinsic(ctx, "llvm.AMDGPU.flbit.i32",
+ dst_type, &arg, 1,
+ AC_FUNC_ATTR_READNONE);
+
+ /* The HW returns the last bit index from MSB, but NIR/TGSI wants
+ * the index from LSB. Invert it by doing "31 - msb". */
+ msb = LLVMBuildSub(ctx->builder, LLVMConstInt(ctx->i32, 31, false),
+ msb, "");
+
+ LLVMValueRef all_ones = LLVMConstInt(ctx->i32, -1, true);
+ LLVMValueRef cond = LLVMBuildOr(ctx->builder,
+ LLVMBuildICmp(ctx->builder, LLVMIntEQ,
+ arg, LLVMConstInt(ctx->i32, 0, 0), ""),
+ LLVMBuildICmp(ctx->builder, LLVMIntEQ,
+ arg, all_ones, ""), "");
+
+ return LLVMBuildSelect(ctx->builder, cond, all_ones, msb, "");
+}
diff --git a/src/amd/common/ac_llvm_build.h b/src/amd/common/ac_llvm_build.h
index e88874ad46b..0ff04e4c703 100644
--- a/src/amd/common/ac_llvm_build.h
+++ b/src/amd/common/ac_llvm_build.h
@@ -182,6 +182,10 @@ void ac_emit_sendmsg(struct ac_llvm_context *ctx,
uint32_t msg,
LLVMValueRef wave_id);
+LLVMValueRef ac_emit_imsb(struct ac_llvm_context *ctx,
+ LLVMValueRef arg,
+ LLVMTypeRef dst_type);
+
#ifdef __cplusplus
}
#endif