From f031e8ad011e9ad95d7c965936da07e3a9c42add Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Fri, 1 Jan 2010 03:32:16 +0000 Subject: Teach codegen to lower llvm.powi to an efficient (but not optimal) multiply sequence when the power is a constant integer. Before, our codegen for std::pow(.., int) always turned into a libcall, which was really inefficient. This should also make many gfortran programs happier I'd imagine. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92388 91177308-0d34-0410-b5e6-96231b3b80d8 --- test/CodeGen/X86/2007-09-27-LDIntrinsics.ll | 53 ++++++++++------------------- test/CodeGen/X86/powi.ll | 11 ++++++ 2 files changed, 29 insertions(+), 35 deletions(-) create mode 100644 test/CodeGen/X86/powi.ll (limited to 'test') diff --git a/test/CodeGen/X86/2007-09-27-LDIntrinsics.ll b/test/CodeGen/X86/2007-09-27-LDIntrinsics.ll index 4a56ee446a..4d6971586c 100644 --- a/test/CodeGen/X86/2007-09-27-LDIntrinsics.ll +++ b/test/CodeGen/X86/2007-09-27-LDIntrinsics.ll @@ -1,47 +1,30 @@ -; RUN: llc < %s | grep powixf2 -; RUN: llc < %s | grep fsqrt -; ModuleID = 'yyy.c' +; RUN: llc < %s | FileCheck %s target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128" target triple = "i686-apple-darwin8" -define x86_fp80 @foo(x86_fp80 %x) { +define x86_fp80 @foo(x86_fp80 %x) nounwind{ entry: - %x_addr = alloca x86_fp80 ; [#uses=2] - %retval = alloca x86_fp80 ; [#uses=2] - %tmp = alloca x86_fp80 ; [#uses=2] - %"alloca point" = bitcast i32 0 to i32 ; [#uses=0] - store x86_fp80 %x, x86_fp80* %x_addr - %tmp1 = load x86_fp80* %x_addr, align 16 ; [#uses=1] - %tmp2 = call x86_fp80 @llvm.sqrt.f80( x86_fp80 %tmp1 ) ; [#uses=1] - store x86_fp80 %tmp2, x86_fp80* %tmp, align 16 - %tmp3 = load x86_fp80* %tmp, align 16 ; [#uses=1] - store x86_fp80 %tmp3, x86_fp80* %retval, align 16 - br label %return - -return: ; preds = %entry - %retval4 = load x86_fp80* %retval ; [#uses=1] - ret x86_fp80 %retval4 + %tmp2 = call x86_fp80 @llvm.sqrt.f80( x86_fp80 %x ) + ret x86_fp80 %tmp2 + +; CHECK: foo: +; CHECK: fldt 4(%esp) +; CHECK-NEXT: fsqrt +; CHECK-NEXT: ret } declare x86_fp80 @llvm.sqrt.f80(x86_fp80) -define x86_fp80 @bar(x86_fp80 %x) { +define x86_fp80 @bar(x86_fp80 %x) nounwind { entry: - %x_addr = alloca x86_fp80 ; [#uses=2] - %retval = alloca x86_fp80 ; [#uses=2] - %tmp = alloca x86_fp80 ; [#uses=2] - %"alloca point" = bitcast i32 0 to i32 ; [#uses=0] - store x86_fp80 %x, x86_fp80* %x_addr - %tmp1 = load x86_fp80* %x_addr, align 16 ; [#uses=1] - %tmp2 = call x86_fp80 @llvm.powi.f80( x86_fp80 %tmp1, i32 3 ) ; [#uses=1] - store x86_fp80 %tmp2, x86_fp80* %tmp, align 16 - %tmp3 = load x86_fp80* %tmp, align 16 ; [#uses=1] - store x86_fp80 %tmp3, x86_fp80* %retval, align 16 - br label %return - -return: ; preds = %entry - %retval4 = load x86_fp80* %retval ; [#uses=1] - ret x86_fp80 %retval4 + %tmp2 = call x86_fp80 @llvm.powi.f80( x86_fp80 %x, i32 3 ) + ret x86_fp80 %tmp2 +; CHECK: bar: +; CHECK: fldt 4(%esp) +; CHECK-NEXT: fld %st(0) +; CHECK-NEXT: fmul %st(1) +; CHECK-NEXT: fmulp %st(1) +; CHECK-NEXT: ret } declare x86_fp80 @llvm.powi.f80(x86_fp80, i32) diff --git a/test/CodeGen/X86/powi.ll b/test/CodeGen/X86/powi.ll new file mode 100644 index 0000000000..c3d68312ce --- /dev/null +++ b/test/CodeGen/X86/powi.ll @@ -0,0 +1,11 @@ +; RUN: llc %s -march=x86 -mcpu=yonah -o - | grep mulsd | count 6 +; Ideally this would compile to 5 multiplies. + +define double @_Z3f10d(double %a) nounwind readonly ssp noredzone { +entry: + %0 = tail call double @llvm.powi.f64(double %a, i32 15) nounwind ; [#uses=1] + ret double %0 +} + +declare double @llvm.powi.f64(double, i32) nounwind readonly + -- cgit v1.2.3